Amine-Catalyzed Highly Regioselective and Stereoselective C(sp(2) )-C(sp(2) ) Cross-Coupling of Naphthols with trans-α,β-Unsaturated Aldehydes.

Chem Asian J 2015 Sep 14;10(9):1859-63. Epub 2015 Jul 14.

Shanghai Key Laboratory of New Drug Design, School of Pharmacy, State Key Laboratory of Bioengineering Reactors, East China University of Science&Technology, 200237, Shanghai, China.

A metal-free C(sp(2) )-C(sp(2) ) cross-coupling approach to highly congested (E)-α-naphtholylenals from simple naphthols and enals is described. The mild reaction conditions with pyridine hydrobromideperbromide (PHBP) as the bromination reagent in the presence of piperidine or diphenylprolinol trimethylsilyl (TMS) ether as promoters enable the process in good yields and with high chemoselectivity, regioselectivity, and stereoselectivity. The process involves an unprecedented pathway of in situ regioselective 4-bromination of 1-naphthols and the subsequent unusual aromatic nucleophilic substitution of the resulting 4-bromo-1-naphthols with the α-C(sp(2) ) of enals through a Michael-type Friedel-Crafts alkylation-dearomatization followed by a cyclopropanation ring-opening cascade process. The noteworthy features of this strategy are highlighted by the highly efficient creation of a C(sp(2) )-C(sp(2) ) bond from readily available unfunctionalized naphthols and enals catalyzed by non-metal, readily available cyclic secondary amines under mild reaction conditions.

Download full-text PDF

Source
http://dx.doi.org/10.1002/asia.201500460DOI Listing
September 2015
3 Reads

Publication Analysis

Top Keywords

csp2 -csp2
12
-csp2 cross-coupling
8
naphthols enals
8
mild reaction
8
reaction conditions
8
reagent presence
4
process good
4
strategy highlighted
4
enable process
4
good yields
4
features strategy
4
noteworthy features
4
high chemoselectivity
4
yields high
4
promoters enable
4
highlighted highly
4
piperidine diphenylprolinol
4
highly efficient
4
trimethylsilyl tms
4
diphenylprolinol trimethylsilyl
4

References

(Supplied by CrossRef)

Ishikura et al.
Nat. Prod. Rep. 2013

Inman et al.
Chem. Sci. 2013

Horton et al.
Chem. Rev. 2003

Posakony et al.
Med. Chem. 2004

Neugebauer et al.
J. Med. Chem. 2008

Kumar et al.
J. Med. Chem. 2008

Han et al.
Mol. Diversity 2011

Booth et al.
1987

Zhu et al.
Acc. Chem. Res. 2015

Similar Publications