Catalytic cross-benzoin/Michael/acetalization cascade for asymmetric synthesis of trifluoromethylated γ-butyrolactones
作者:Xiang-Hong He、Lei Yang、Wei Huang、Qian Zhao、Xiao-Li Pan、Dao-Feng Jiang、Ming-Cheng Yang、Cheng Peng、Bo Han
DOI:10.1039/c6ra03571j
日期:——
A sequential NHC-amine catalyticcascade reaction has been developed to assemble aromatic aldehydes, trifluoroacetaldehyde ethyl hemiacetal and enals asymmetrically into CF3-substituted chiral γ-butyrolactone derivatives featuring vicinal quaternary and tertiary stereocenters. This approach incorporates a highly chemoselective intermolecular cross-benzoin reaction and a highly regioselective Michael-acetalization
An NHC-Catalyzed Cross-Benzoin–Esterification Sequential Reaction for the Synthesis of Trifluoromethyl-Substituted α,β-Unsaturated Esters
作者:Cheng Peng、Bo Han、Qian Zhao、Li-Ying Feng、Wei Huang、Xiang-Hong He
DOI:10.1055/s-0035-1561631
日期:——
Efficient preparation of synthetically important CF3-containing α,β-unsaturatedesters is described using an NHC-catalyzed multicomponent reaction. This approach combines sequential NHC-mediated HOMO and LUMO activation to produce a C–C bond and C–O bond in a one-pot operation.
<i>N</i>-Heterocyclic Carbene Catalyzed Highly Chemoselective Intermolecular Crossed Acyloin Condensation of Aromatic Aldehydes with Trifluoroacetaldehyde Ethyl Hemiacetal
作者:Bandaru T. Ramanjaneyulu、Sriram Mahesh、Ramasamy Vijaya Anand
DOI:10.1021/ol502581b
日期:2015.1.2
A highlychemoselectiveintermolecularcrossed acyloin condensation between aromaticaldehydes and trifluoroacetaldehyde ethyl hemiacetal has been developed under mild reaction conditions using N-heterocyclic carbene as a catalyst. A wide range of aromaticaldehydes bearing electron-withdrawing and -donating substituents underwent a smooth transformation to their corresponding trifluoromethyl containing