36 results match your criteria Organic Process Research and Development [Journal]

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Efficient Electrocatalytic Reduction of Furfural to Furfuryl Alcohol in a Microchannel Flow Reactor.

Org Process Res Dev 2019 Mar 8;23(3):403-408. Epub 2019 Feb 8.

Department of Chemical Engineering and Chemistry, Sustainable Process Engineering, Micro Flow Chemistry & Synthetic Methodology, Eindhoven University of Technology, De Rondom 70 (Helix, STO 1.37), 5612 AP Eindhoven, The Netherlands.

Furfural is considered to be an essential biobased platform molecule. Recently, its electrocatalytic hydrogenation is regarded as a more environmentally friendly process compared to traditional catalytic hydrogenation. In this study, a new, continuous-flow approach enabling furfural electrocatalytic reduction was developed. Read More

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http://dx.doi.org/10.1021/acs.oprd.8b00428DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6423986PMC

Parallel, Large-Scale, and Long Synthetic Oligodeoxynucleotide Purification Using the Catching Full-Length Sequence by Polymerization Technique.

Org Process Res Dev 2018 Sep 31;22(9):1282-1288. Epub 2018 Aug 31.

Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.

The catching by polymerization synthetic oligodeoxynucleotide (ODN) purification technique was shown to be potentially suitable for high throughput purification by purifying 12 ODNs simultaneously, to be convenient for large-scale purification by purifying at 60 μmol synthesis scale, and to be highly powerful for long ODN purification by purifying ODNs as long as 303-mer. LC-MS analysis indicated that the ODNs purified with the technique have excellent purity. Read More

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http://pubs.acs.org/doi/10.1021/acs.oprd.8b00209
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http://dx.doi.org/10.1021/acs.oprd.8b00209DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6428204PMC
September 2018
7 Reads

Continuous Platform to Generate Nitroalkanes On-Demand (in situ) using Peracetic Acid-Mediated Oxidation in a PFA Pipes-in-Series Reactor.

Org Process Res Dev 2018 Aug 19;22(8):971-977. Epub 2018 Jul 19.

Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, United States.

The synthetic utility of the aza-Henry reaction can be diminished on scale by potential hazards associated with the use of peracid to prepare nitroalkane substrates, and the nitroalkanes themselves. In response, a continuous and scalable chemistry platform to prepare aliphatic nitroalkanes on-demand is reported, using the oxidation of oximes with peracetic acid and direct reaction of the nitroalkane intermediate in an aza-Henry reaction. A uniquely designed pipes-in-series plug flow tube reactor addresses a range of process challenges including stability and safe handling of peroxides and nitroalkanes. Read More

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http://dx.doi.org/10.1021/acs.oprd.8b00113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6424520PMC
August 2018
1 Read

Biobased Chemicals: 1,2,4-Benzenetriol, Selective Deuteration and Dimerization to Bifunctional Aromatic Compounds.

Org Process Res Dev 2018 Dec 9;22(12):1663-1671. Epub 2018 Nov 9.

Department of Chemical Engineering, ENTEG, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.

1,2,4-Benzenetriol (BTO), sourced from the carbohydrate-derived platform chemical 5-hydroxylmethylfurfural (HMF), is an interesting starting point for the synthesis of various biobased aromatic products. However, BTO readily undergoes dimerization and other reactions under mild conditions, making analysis and isolation challenging. To both control and utilize the reactivity of BTO to produce biobased building blocks, its reactivity needs to be better understood. Read More

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http://dx.doi.org/10.1021/acs.oprd.8b00303DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6369680PMC
December 2018
3 Reads

Toward Upscaled Biocatalytic Preparation of Lactone Building Blocks for Polymer Applications.

Org Process Res Dev 2018 Jul 12;22(7):803-812. Epub 2018 Jun 12.

Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Brightlands Chemelot Campus, Urmonderbaan 22, 6167 RD Geleen, The Netherlands.

Although Baeyer-Villiger monooxygenases (BVMOs) have gained attention in recent years, there are few cases of their upscaled application for lactone synthesis. A thermostable cyclohexanone monooxygenase from (TmCHMO) was applied to the oxidation of 3,3,5-trimethylcyclohexanone using a glucose dehydrogenase (GDH) for cofactor regeneration. The reaction progress was improved by optimizing the biocatalyst loading, with investigation into oxygen limitations. Read More

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http://pubs.acs.org/doi/10.1021/acs.oprd.8b00079
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http://dx.doi.org/10.1021/acs.oprd.8b00079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6156103PMC
July 2018
2 Reads

Continuous-Flow In-Line Solvent-Swap Crystallization of Vitamin D.

Org Process Res Dev 2018 Feb 27;22(2):178-189. Epub 2017 Dec 27.

Graz University of Technology, Institute of Process and Particle Engineering, NAWI Graz, Inffeldgasse 13, 8010 Graz, Austria.

A continuous tandem in-line evaporation-crystallization is presented. The process includes an in-line solvent-swap step, suitable to be coupled to a capillary based cooler. As a proof of concept, this setup is tested in a direct in-line acetonitrile mediated crystallization of Vitamin D. Read More

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http://dx.doi.org/10.1021/acs.oprd.7b00351DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5997464PMC
February 2018
1 Read

Microflow High-p,T Intensification of Vitamin D Synthesis Using an Ultraviolet Lamp.

Org Process Res Dev 2018 Feb 20;22(2):147-155. Epub 2017 Dec 20.

Micro Flow Chemistry and Process Technology, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.

Herewith a new process concept for synthesis is presented which combines both UV-photoirradiation and high-p,T intensification (photo-high-p,T) in continuous flow. The application of this procedure to Vitamin D synthesis promotes thermal shifting of the equilibrium from the reaction intermediate to the product. This is enabled by microreactors which allow operation under harsh conditions such as the high temperature used here. Read More

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http://dx.doi.org/10.1021/acs.oprd.7b00318DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5828710PMC
February 2018
6 Reads

Investigation of the Stereoselective Synthesis of the Indane Dimer PH46A, a New Potential Anti-inflammatory Agent.

Org Process Res Dev 2017 Dec 27;21(12):1972-1979. Epub 2017 Nov 27.

Trino Therapeutics Ltd, The Tower, Trinity Technology & Enterprise Campus, Dublin 2, Ireland.

PH46A, belonging to a class of 1,2-Indane dimers, has been developed by our research group as a potential therapeutic agent for the treatment of inflammatory and autoimmune diseases. The initial synthetic route to PH46A gave a low overall yield, due in large part to the generation of undesired diastereoisomer and the unwanted enantiomer (,)- during the synthesis. The aim of this work was to carry out a comprehensive investigation into the stereoselective synthesis of PH46A. Read More

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http://dx.doi.org/10.1021/acs.oprd.7b00258DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5814955PMC
December 2017
6 Reads

Process Safety Assessment of the Iron-Catalyzed Direct Olefin Diazidation for the Expedient Synthesis of Vicinal Primary Diamines.

Org Process Res Dev 2017 Dec 8;21(12):2068-2072. Epub 2017 Nov 8.

Department of Chemistry, Georgia State University, 100 Piedmont Avenue SE, Atlanta, Georgia 30303, United States.

We report herein a process safety assessment of the iron-catalyzed direct olefin diazidation for the preparation of a broad range of synthetically valuable vicinal primary diamines. Differential scanning calorimetry analysis of the corresponding reagents, intermediates, and a list of representative diazide/diaminium salt products revealed that all of them are thermal stable at the reaction temperature. The drop weight test of the diazides suggested that they are moderately impact-sensitive. Read More

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http://dx.doi.org/10.1021/acs.oprd.7b00312DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5773106PMC
December 2017
8 Reads

Continuous Photo-Oxidation in a Vortex Reactor: Efficient Operations Using Air Drawn from the Laboratory.

Org Process Res Dev 2017 Jul 3;21(7):1042-1050. Epub 2017 Jul 3.

School of Chemistry, Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD, U.K.

We report the construction and use of a vortex reactor which uses a rapidly rotating cylinder to generate Taylor vortices for continuous flow thermal and photochemical reactions. The reactor is designed to operate under conditions required for vortex generation. The flow pattern of the vortices has been represented using computational fluid dynamics, and the presence of the vortices can be easily visualized by observing streams of bubbles within the reactor. Read More

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http://dx.doi.org/10.1021/acs.oprd.7b00153DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5526652PMC
July 2017
11 Reads

Practical Synthesis of the Bicyclic Darunavir Side Chain: (3,3a,6a)-Hexahydrofuro[2,3-]furan-3-ol from Monopotassium Isocitrate.

Org Process Res Dev 2017 Jan 14;21(1):98-106. Epub 2016 Dec 14.

Clinton Health Access Initiative, 800 North Five Points Road, West Chester, Pennsylvania 19380, United States.

A practical synthesis of (3,3a,6a)-hexahydrofuro[2,3-]furan-3-ol-a key intermediate in the synthesis of darunavir-from monopotassium isocitrate is described. The isocitric acid salt, obtained from a high-yielding fermentation fed by sunflower oil, was converted in several steps to a tertiary amide. This amide, along with the compound's ester functionalities, was reduced with lithium aluminum hydride to give, on acidic workup, a transient aminal-triol. Read More

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http://dx.doi.org/10.1021/acs.oprd.6b00377DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5437813PMC
January 2017
30 Reads

Development of a Scalable Process for the Synthesis of DNDI-VL-2098: A Potential Preclinical Drug Candidate for the Treatment of Visceral Leishmaniasis.

Org Process Res Dev 2017 Jan 6;21(1):52-59. Epub 2016 Dec 6.

Drugs for Neglected Diseases initiative (DNDi), 15 Chemin Louis Dunant, 1202 Geneva, Switzerland.

A process suitable for kilogram-scale synthesis of (2)-2-methyl-6-nitro-2-{[4-(trifluoromethoxy)phenoxy]methyl}-2,3-dihydroimidazo[2,1-][1,3]oxazole (DNDI-VL-2098, ), a preclinical drug candidate for the treatment of visceral leishmaniasis, is described. The four-step synthesis of the target compound involves the Sharpless asymmetric epoxidation of 2-methyl-2-propen-1-ol, . Identification of a suitable synthetic route using retrosynthetic analysis and development of a scalable process to access several kilograms of are illustrated. Read More

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http://dx.doi.org/10.1021/acs.oprd.6b00331DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5437808PMC
January 2017
30 Reads

Scalable Synthesis and Purification of Acetylated Phosphatidyl Choline Headgroup.

Org Process Res Dev 2017 Feb 24;21(2):177-181. Epub 2017 Jan 24.

Department of Pharmaceutical Sciences, Vermont Campus, Albany College of Pharmacy and Health Sciences, 261 Mountain View Drive, Colchester, Vermont 05446, Unites States.

The acetylated headgroup of the most abundant mammalian phospholipid, 1,2-diacetyl-3--phosphatidyl choline (DAcPC), has several important applications in research. For instance, it can be dissolved in the same amount of water as in the fluid PC bilayer, to create a surrogate of a PC headgroup stratum, for studying solvation of small molecules and the influence of their structure on the process. In contrast to PC derivatives with longer acyl chains, DAcPC does not self-aggregate, rendering the aqueous solution homogeneous and suitable for simplified analyses of interactions of molecules with the headgroups. Read More

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http://dx.doi.org/10.1021/acs.oprd.6b00261DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6380518PMC
February 2017
1 Read

Advances in Photocatalysis: A Microreview of Visible Light Mediated Ruthenium and Iridium Catalyzed Organic Transformations.

Org Process Res Dev 2016 Jul 28;20(7):1156-1163. Epub 2016 Jun 28.

Aspira Scientific, Milpitas, California 95035.

Photocatalytic organic transformations utilizing ruthenium and iridium complexes have garnered significant attention due to the access they provide to new synthetic spaces through new reaction mechanisms. A survey of the photophysical data and the diversity of transformations that may be accomplished utilizing commercially available photocatalysts is contained herein. Read More

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http://dx.doi.org/10.1021/acs.oprd.6b00101DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4972501PMC
July 2016
10 Reads

Stereospecific Nickel-Catalyzed Cross-Coupling Reactions of Benzylic Ethers with Isotopically-Labeled Grignard Reagents.

Org Process Res Dev 2015 Oct 11;19(10):1356-1359. Epub 2015 Sep 11.

Department of Chemistry, University of California , Irvine, California 92697-2025, United States.

In this manuscript we highlight the potential of stereospecific nickel-catalyzed cross-coupling reactions for applications in the pharmaceutical industry. Using an inexpensive and sustainable nickel catalyst, we report a gram-scale Kumada cross-coupling reaction. Reactions are highly stereospecific and proceed with inversion at the benzylic position. Read More

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http://dx.doi.org/10.1021/acs.oprd.5b00148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4955521PMC
October 2015
11 Reads

Palladium-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to α,β-Unsaturated Cyclic Electrophiles.

Org Process Res Dev 2015 Aug 2;19(8):974-981. Epub 2015 Jul 2.

The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States.

This account describes our laboratory's efforts in the development of a palladium-catalyzed asymmetric conjugate addition of arylboronic acids to cyclic conjugate acceptors. Specifically, we highlight the study of this transformation in the following areas: (a) construction of all-carbon quaternary stereocenters, (b) elucidation of the reaction mechanism, Read More

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http://dx.doi.org/10.1021/acs.oprd.5b00169DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4896742PMC
August 2015
14 Reads

Development of an Intermittent-Flow Enantioselective Aza-Henry Reaction Using an Arylnitromethane and Homogeneous Brønsted Acid-Base Catalyst with Recycle.

Org Process Res Dev 2016 Feb 1;20(2):215-226. Epub 2016 Feb 1.

Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, United States.

A stereoselective aza-Henry reaction between an arylnitromethane and Boc-protected aryl aldimine using a homogeneous Brønsted acid-base catalyst was translated from batch format to an automated intermittent-flow process. This work demonstrates the advantages of a novel intermittent-flow setup with product crystallization and slow reagent addition which is not amenable to the standard continuous equipment: plug flow tube reactor (PFR) or continuous stirred tank reactor (CSTR). A significant benefit of this strategy was the integration of an organocatalytic enantioselective reaction with straightforward product separation, including recycle of the catalyst, resulting in increased intensity of the process by maintaining high catalyst concentration in the reactor. Read More

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http://dx.doi.org/10.1021/acs.oprd.5b00245DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4821467PMC
February 2016
18 Reads

Experimental Limiting Oxygen Concentrations for Nine Organic Solvents at Temperatures and Pressures Relevant to Aerobic Oxidations in the Pharmaceutical Industry.

Org Process Res Dev 2015 Nov 6;19(11):1537-1543. Epub 2014 Dec 6.

Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.

Applications of aerobic oxidation methods in pharmaceutical manufacturing are limited in part because mixtures of oxygen gas and organic solvents often create the potential for a flammable atmosphere. To address this issue, limiting oxygen concentration (LOC) values, which define the minimum partial pressure of oxygen that supports a combustible mixture, have been measured for nine commonly used organic solvents at elevated temperatures and pressures. The solvents include acetic acid, -methylpyrrolidone, dimethyl sulfoxide, -amyl alcohol, ethyl acetate, 2-methyltetrahydrofuran, methanol, acetonitrile, and toluene. Read More

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http://dx.doi.org/10.1021/op500328fDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4655819PMC
November 2015
10 Reads

Why You Really Should Consider Using Palladium-Catalyzed Cross-Coupling of Silanols and Silanolates.

Org Process Res Dev 2015;19(8):982-994

Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL 61801.

The transition metal-catalyzed cross-coupling of organometallic nucleophiles derived from tin, boron, and zinc with organic electrophiles enjoys a preeminent status among modern synthetic methods for the formation of carbon-carbon bonds. In recent years, organosilanes have emerged as viable alternatives to the conventional reagents, with the added benefits of low cost, low toxicity and high chemical stability. However, silicon-based cross-coupling reactions often require heating in the presence of a fluoride source, which has significantly hampered their widespread acceptance. Read More

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http://dx.doi.org/10.1021/acs.oprd.5b00201DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4608042PMC
January 2015
4 Reads

Closed-Loop Multitarget Optimization for Discovery of New Emulsion Polymerization Recipes.

Org Process Res Dev 2015 Aug 30;19(8):1049-1053. Epub 2015 Jul 30.

Department of Chemical Engineering and Biotechnology, University of Cambridge , Pembroke Street, New Museums Site, Cambridge CB2 3RA, United Kingdom.

Self-optimization of chemical reactions enables faster optimization of reaction conditions or discovery of molecules with required target properties. The technology of self-optimization has been expanded to discovery of new process recipes for manufacture of complex functional products. A new machine-learning algorithm, specifically designed for multiobjective target optimization with an explicit aim to minimize the number of "expensive" experiments, guides the discovery process. Read More

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http://dx.doi.org/10.1021/acs.oprd.5b00210DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4579860PMC
August 2015
6 Reads

Late-Stage Fluorination: From Fundamentals to Application.

Org Process Res Dev 2014 Apr 11;18(4):474-480. Epub 2014 Mar 11.

Department of Chemistry and Chemical Biology, Harvard University , 12 Oxford Street, Cambridge, Massachusetts 02138, United States.

In this brief account, we review work from our lab with a focus on late-stage introduction of fluorine and fluorinated functional groups into small molecules. We attempt to highlight practical developments, which we believe may have potential for industrial applications, and critically reflect on developments that may not yet meet the bar for practical use. Read More

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http://dx.doi.org/10.1021/op400349gDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4372057PMC
April 2014
54 Reads

Continuous Flow Aerobic Alcohol Oxidation Reactions Using a Heterogeneous Ru(OH) /AlO Catalyst.

Org Process Res Dev 2014 Nov 23;18(11):1503-1508. Epub 2014 Sep 23.

Department of Chemical and Biological Engineering and Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.

Ru(OH) /AlO is among the more versatile catalysts for aerobic alcohol oxidation and dehydrogenation of nitrogen heterocycles. Here, we describe the translation of batch reactions to a continuous-flow method that enables high steady-state conversion and single-pass yields in the oxidation of benzylic alcohols and dehydrogenation of indoline. A dilute source of O (8% in N) was used to ensure that the reaction mixture, which employs toluene as the solvent, is nonflammable throughout the process. Read More

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http://pubs.acs.org/doi/10.1021/op5002676
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http://dx.doi.org/10.1021/op5002676DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4299400PMC
November 2014
14 Reads

Preparative Synthesis of Highly Substituted Tetrahydropyridines via a Rh(I)-Catalyzed C-H Functionalization Sequence.

Org Process Res Dev 2014 Sep 29;18(9):1105-1109. Epub 2014 Aug 29.

Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.

We report a Rh(I)-catalyzed C-H activation/alkenylation/electrocyclization cascade and subsequent reduction for the synthesis of highly substituted tetrahydropyridines. These products can be accessed on a gram scale with low catalyst loadings and at high reaction concentrations. Additionally, a modified Rh-catalyst, prepared from [RhCl(cod)] as a robust bench-stable precatalyst was developed to enable straightforward reaction set up without the use of a glovebox. Read More

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http://dx.doi.org/10.1021/op500225cDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4183668PMC
September 2014
8 Reads

Convergent Synthesis of Diverse Tetrahydropyridines via Rh(I)-Catalyzed C-H Functionalization Sequences.

Org Process Res Dev 2014 Sep 29;18(9):1097-1104. Epub 2014 Aug 29.

Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.

A Rh-catalyzed C-H bond activation/alkenylation/electrocyclization cascade reaction provides diverse 1,2-dihydropyridines from simple and readily available precursors. The reaction can be carried out at low (<1%) Rh-catalyst loadings, and the use of the robust, air-stable Rh precatalyst, [RhCl(cod)], enables the cascade reaction to be easily performed on the benchtop. The 1,2-dihydropyridine products serve as extremely versatile synthetic intermediates for further elaboration often without isolation. Read More

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http://dx.doi.org/10.1021/op500224xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4183667PMC
September 2014
6 Reads

PhenoFluor: Practical Synthesis, New Formulation, and Deoxyfluorination of Heteroaromatics.

Org Process Res Dev 2014 Aug 23;18(8):1041-1044. Epub 2014 Jul 23.

Department of Chemistry and Chemical Biology, Harvard University , 12 Oxford Street, Cambridge, Massachusetts 02138, United States.

We report a practical synthesis method of the reagent PhenoFluor on decagram scale, provide a new formulation of PhenoFluor as a toluene solution, which should decrease challenges associated with the moisture sensitivity of the reagent, and expand the substrate scope of deoxyfluorination with PhenoFluor to heteroaromatics. Read More

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http://dx.doi.org/10.1021/op500121wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4144717PMC
August 2014
26 Reads

Influence of Cofactor Regeneration Strategies on Preparative-Scale, Asymmetric Carbonyl Reductions by Engineered

Org Process Res Dev 2014 Jun 17;18(6):793-800. Epub 2014 Feb 17.

Department of Chemistry, University of Florida , 126 Sisler Hall, Gainesville, Florida 32611, United States.

This study was designed to determine whether whole cells or crude enzyme extracts are more effective for preparative-scale ketone reductions by dehydrogenases as well as learning which cofactor regeneration scheme is most effective. Based on results from three representative ketone substrates (an α-fluoro-β-keto ester, a -trifluoromethylated acetophenone, and a symmetrical β-diketone), our results demonstrate that several nicotinamide cofactor regeneration strategies can be applied to preparative-scale dehydrogenase-catalyzed reactions successfully. Read More

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http://dx.doi.org/10.1021/op400312nDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4105172PMC
June 2014
13 Reads

Polymorph Discrimination using Low Wavenumber Raman Spectroscopy.

Org Process Res Dev 2013 Jul 20;17(7):976-980. Epub 2013 Jun 20.

Department of Chemistry and the Macromolecular Science and Engineering Program, University of Michigan, Ann Arbor, Michigan 48109, United States.

Characterization of crystalline polymorphs and their quantitation has become an integral part of the pre-clinical drug development process. Raman spectroscopy is a powerful technique for the rapid identification of phases of pharmaceuticals. In the present work we demonstrate the use of low wavenumber Raman vibrational spectroscopy (including phonon measurement) for discrimination among polymorphs. Read More

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http://dx.doi.org/10.1021/op400102eDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5026242PMC
July 2013
5 Reads

Asymmetric Preparation of -, -, and -Amines Employing Selected Biocatalysts.

Org Process Res Dev 2013 May 22;17(5):751-759. Epub 2013 Apr 22.

Department of Chemistry, University of Graz , Heinrichstrasse 28, A-8010 Graz, Austria ; ACIB GmbH c/o Department of Chemistry, University of Graz, Heinrichstrasse 28, A-8010 Graz, Austria.

This account focuses on the application of ω-transaminases, lyases, and oxidases for the preparation of amines considering mainly work from our own lab. Examples are given to access α-chiral primary amines from the corresponding ketones as well as terminal amines from primary alcohols via a two-step biocascade. 2,6-Disubstituted piperidines, as examples for secondary amines, are prepared by biocatalytical regioselective asymmetric monoamination of designated diketones followed by spontaneous ring closure and a subsequent diastereoselective reduction step. Read More

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http://dx.doi.org/10.1021/op4000237DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3688330PMC
May 2013
32 Reads

A practical and scalable manufacturing process for an anti-fungal agent, Nikkomycin Z.

Org Process Res Dev 2013 Feb 17;17(2):265-272. Epub 2013 Jan 17.

Institute for Therapeutics Discovery and Development and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States ; BioTechnology Institute, University of Minnesota, Saint Paul, Minnesota 55108, United States.

A scalable and reliable manufacturing process for Nikkomycin Z HCl on a 170 g scale has been developed and optimized. The process is characterized by a 2.3 g/L fermentation yield, 79% purification yield, and >98% relative purity of the final product. Read More

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http://dx.doi.org/10.1021/op3003294DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3579645PMC
February 2013
14 Reads

Pd and Mo Catalyzed Asymmetric Allylic Alkylation.

Authors:
Barry M Trost

Org Process Res Dev 2012 Feb 13;16(2):185-194. Epub 2012 Jan 13.

Department of Chemistry, Stanford University, Stanford, CA 94305-5080.

The ability to control the alkylation of organic substrates becomes ever more powerful by using metal catalysts. Among the major benefits of metal catalysis is the possibility to perform such processes asymmetrically using only catalytic amounts of the chiral inducing agent which is a ligand to the metal of the catalyst. A unique aspect of asymmetric metal catalyzed processes is the fact that many mechanisms exist for stereoinduction. Read More

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http://dx.doi.org/10.1021/op200294rDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3377172PMC
February 2012
4 Reads

Allylic Amines as Key Building Blocks in the Synthesis of (E)-Alkene Peptide Isosteres.

Org Process Res Dev 2012 ;16(1):26-34

Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA.

Nucleophilic imine additions with vinyl organometallics have developed into efficient, high yielding, and robust methodologies to generate structurally diverse allylic amines. We have used the hydrozirconation-transmetalation-imine addition protocol in the synthesis of allylic amine intermediates for peptide bond isosteres, phosphatase inhibitors, and mitochondria-targeted peptide mimetics. The gramicidin S-derived XJB-5-131 and JP4-039 and their analogs have been prepared on up to 160 g scale for preclinical studies. Read More

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http://dx.doi.org/10.1021/op2002613DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3272643PMC
January 2012
5 Reads

Unlocking Hydrogenation for C-C Bond Formation: A Brief Overview of Enantioselective Methods.

Org Process Res Dev 2011 Nov;15(6):1236-1242

University of Texas at Austin, Department of Chemistry and Biochemistry, 1 University Station - A5300, Austin, TX 78712-1167, USA.

Hydrogenation of π-unsaturated reactants in the presence of carbonyl compounds or imines promotes reductive C-C coupling, providing a byproduct-free alternative to stoichiometric organometallic reagents in an ever-increasing range of C=X (X = O, NR) additions. Under transfer hydrogenation conditions, hydrogen exchange between alcohols and π-unsaturated reactants triggers generation of electrophile-nucleophile pairs, enabling carbonyl addition directly from the alcohol oxidation level, bypassing discrete alcohol oxidation and generation of stoichiometric byproducts. Read More

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http://dx.doi.org/10.1021/op200195mDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3224080PMC
November 2011
9 Reads

Rhodium-Catalyzed C-H Amination - An Enabling Method for Chemical Synthesis.

Authors:
J Du Bois

Org Process Res Dev 2011 Jul;15(4):758-762

Department of Chemistry, Stanford University, Stanford CA 94305-5080.

Reaction methods for selective C-H amination are finding ever-increasing utility for the preparation of nitrogen-derived fine chemicals. This brief account highlights the remarkable versatility of dirhodium-based catalysts for promoting oxidation of aliphatic C-H centers in both intra- and intermolecular reaction processes. Read More

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http://dx.doi.org/10.1021/op200046vDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3143484PMC
July 2011
5 Reads

First Multi-gram Preparation SCP-123, A Novel Water Soluble Analgesic.

Org Process Res Dev 2009 Jul;13(4):820

Department of Chemistry, University of New Orleans, New Orleans, LA 70148.

A short multi-gram process for the preparation of the analgesic compound SCP-123 (4) and its sodium salt has been developed. Read More

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http://pubs.acs.org/doi/abs/10.1021/op900113b
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http://dx.doi.org/10.1021/op900113bDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2814521PMC
July 2009
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Enantioselective Synthesis of Hydrobenzofuranones Using an Asymmetric Desymmetrizing Intramolecular Stetter Reaction of Cyclohexadienones.

Org Process Res Dev 2007 ;11(3):598-604

Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.

A series of cyclohexadienones were synthesized by dearomatization of phenols followed by Dess-Martin oxidation. Asymmetric intramolecular Stetter reactions of these substrates provide hydrobenzofuranones in good to excellent yields and excellent stereoselectivities. Up to three stereocenters as well as quaternary stereocenter are formed from polysubstituted substrates. Read More

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http://dx.doi.org/10.1021/op600278fDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2709411PMC
January 2007
7 Reads

Refined Synthesis of 2,3,4,5-Tetrahydro-1,3,3-trimethyldipyrrin, a Deceptively Simple Precursor to Hydroporphyrins.

Org Process Res Dev 2005 ;9(5):651-659

Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA. Email:

2,3,4,5-Tetrahydro-1,3,3-trimethyldipyrrin (1) is a crucial building block in the rational synthesis of chlorins and oxochlorins. The prior 5-step synthesis of 1 from pyrrole-2-carboxaldehyde (2) employed relatively simple and well-known reactions yet suffered from several drawbacks, including limited scale (>/= 0.5 g of 1 per run). Read More

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http://dx.doi.org/10.1021/op050087eDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2614668PMC
January 2005
10 Reads
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