作者:Daniel H. Paull、Chao Fang、James R. Donald、Andrew D. Pansick、Stephen F. Martin
DOI:10.1021/ja305117m
日期:2012.7.11
highly enantioselectivebromolactonizations of a number of structurally distinct unsaturated acids. Like some known catalysts, this catalyst promotes highly enantioselectivebromolactonizations of 4- and 5-aryl-4-pentenoic acids, but it also catalyzes the highly enantioselectivebromolactonizations of 5-alkyl-4(Z)-pentenoic acids. These reactions represent the first catalytic bromolactonizations of alkyl-substituted
Enantioselective Iodolactonization of Disubstituted Olefinic Acids Using a Bifunctional Catalyst
作者:Chao Fang、Daniel H. Paull、J. Caleb Hethcox、Christopher R. Shugrue、Stephen F. Martin
DOI:10.1021/ol3030555
日期:2012.12.21
The enantioselectiveiodolactonizations of a series of diversely substituted olefinic carboxylic acids are promoted by a BINOL-derived, bifunctional catalyst. Reactions involving 5-alkyl- and 5-aryl-4(Z)-pentenoic acids and 6-alkyl- and 6-aryl-5(Z)-hexenoic acids provide the corresponding γ- and δ-lactones having stereogenic C–I bonds in excellent yields and >97:3 er. Significantly, this represents
BINOL 衍生的双功能催化剂促进了一系列不同取代的烯烃羧酸的对映选择性碘内酯化。涉及 5-烷基-和 5-芳基-4( Z )-戊烯酸和 6-烷基-和 6-芳基-5( Z )-己烯酸的反应提供相应的具有立体异构 C-I 键的 γ-和 δ-内酯以优异的产量和 >97:3 er。值得注意的是,这代表了第一种以高对映选择性促进溴和碘内酯化的有机催化剂。还证明了该催化剂诱导外消旋不饱和酸的动力学拆分的潜力。