The benzonitrile unit is widely found in natural products, pharmaceuticals, and agrochemicals. Synthesis of benzonitriles has received considerable interests from the chemical community over the last few decades. Present synthetic protocols mainly rely on the pre-existing benzene core to install a cyano moiety. A new NHC-catalyzed [4 + 2]-benzannulation protocol is reported to assemble the benzonitrile
Organocatalytic Asymmetric Synthesis of Chiral Pyrrolizines by Cascade Conjugate Addition−Aldol Reactions
作者:Ju-Yeon Bae、Hyo-Jun Lee、Seok-Ho Youn、Su-Hyun Kwon、Chang-Woo Cho
DOI:10.1021/ol101811c
日期:2010.10.1
N-centered heteroaromatic nucleophile for organocatalyticcascadereactions, pyrroles underwent the enantio- and diastereoselective organocatalyticcascade conjugate addition−aldol reactions of α,β-unsaturated aldehydes that afford the highly functionalized chiral pyrrolizines bearing three consecutivestereocenters in good yields, high enantioselectivities (90−98% ee), and excellent diastereoselectivities
Enantioselective N-heterocyclic carbene-catalyzed nucleophilic dearomatization of alkyl pyridiniums
作者:Darrin M. Flanigan、Tomislav Rovis
DOI:10.1039/c7sc02648j
日期:——
NHC-catalyzed nucleophilic dearomatization of alkyl pyridiniums has been achieved to generate 1,4-dihydropyridines with high enantioselectivity. This is a rare example of catalytic, asymmetric addition of a nucleophile to the activated pyridinium that prefers C-4 functionalization leading to the 1,4-dihydropyridine with high selectivity.