Publications by authors named "Seok-Ho Youn"

2 Publications

  • Page 1 of 1

Organocatalytic enantioselective formal synthesis of bromopyrrole alkaloids via aza-Michael addition.

Org Biomol Chem 2011 Oct 27;9(22):7734-41. Epub 2011 Sep 27.

Department of Chemistry, Kyungpook National University, Daegu, Republic of Korea.

An unprecedented organocatalytic enantioselective formal synthesis of bromopyrrole alkaloid natural products is reported. An organocatalytic aza-Michael addition using pyrroles as the N-centered nucleophile is utilized as the enantioselective step to construct the nitrogen-substituted stereogenic carbon center in bromopyrrole alkaloids in good yield and excellent enantioselectivity. The aza-Michael product is converted via lactamization using a Staudinger-type reductive cyclization to the key intermediate, which was previously used in the total synthesis of bromopyrrole alkaloid natural products.
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http://dx.doi.org/10.1039/c1ob06078cDOI Listing
October 2011

Organocatalytic asymmetric synthesis of chiral pyrrolizines by cascade conjugate addition-aldol reactions.

Org Lett 2010 Oct;12(19):4352-5

Department of Chemistry, Kyungpook National University, Daegu 702-701, Republic of Korea.

As the first N-centered heteroaromatic nucleophile for organocatalytic cascade reactions, pyrroles underwent the enantio- and diastereoselective organocatalytic cascade conjugate addition-aldol reactions of α,β-unsaturated aldehydes that afford the highly functionalized chiral pyrrolizines bearing three consecutive stereocenters in good yields, high enantioselectivities (90-98% ee), and excellent diastereoselectivities (>20:1 dr in all cases).
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http://dx.doi.org/10.1021/ol101811cDOI Listing
October 2010