Enantioseparation of benzazoles and benzanilides on polysaccharide-based chiral columns
作者:Takateru Kubota、Naotaka Sawada、Lili Zhou、Christopher J. Welch
DOI:10.1002/chir.20732
日期:2010.5.5
The chiral recognition ability of the polysaccharide‐based chiralcolumns (Chiralpak AD‐RH, Chiralpak AS‐RJ, Chiralpak IC, Chiralcel OD‐RH, and Chiralcel OJ‐RH) for the benzazoles and the benzanilides was evaluated under reversed phase conditions. The columns showed the high chiral recognition ability for a wide range of benzazoles and benzanilides. Twenty‐one racemates were used for the evaluation
Regio- and enantioselective functionalization of heteroareneC–H bonds in the absence of directing groups is a long-standing challenge in the field of C–H activation. Herein, we present an approach involving nickel-catalyzed intermolecular enantioselective C–H alkylation of heteroarenes. The process can be carried out under mild conditions using nickel(0) catalysts with N-heterocyclic carbene (NHC)
A catalytic asymmetric alkylation of azoles with secondary 1‐arylalkyl bromides through direct C−H functionalization is reported. Under blue‐light photoexcitation, a copper(I)/carbazole‐based bisoxazoline (CbzBox) catalytic system exhibits good reactivity and high stereoselectivity, thus offering an efficient strategy for the construction of chiral alkyl azoles. These reactions proceed at low temperature