The Catalytic Asymmetric Intermolecular Prins Reaction
作者:C. David Díaz-Oviedo、Rajat Maji、Benjamin List
DOI:10.1021/jacs.1c10245
日期:2021.12.15
Despite their significant potential, catalytic asymmetric reactions of olefins with formaldehyde are rare and metal-free approaches have not been previously disclosed. Here we describe an enantioselective intermolecular Prins reaction of styrenes and paraformaldehyde to form 1,3-dioxanes, using confined imino-imidodiphosphate (iIDP) Brønsted acid catalysts. Isotope labeling experiments and computations
尽管它们具有巨大的潜力,但烯烃与甲醛的催化不对称反应是罕见的,并且以前没有公开过不含金属的方法。在这里,我们描述了苯乙烯和多聚甲醛的对映选择性分子间 Prins 反应以形成 1,3-二恶烷,使用受限的亚氨基-亚氨基二磷酸 ( i IDP) 布朗斯台德酸催化剂。同位素标记实验和计算表明酸活化甲醛低聚物向烯烃中的协同、高度异步添加。对映体富集的 1,3-二恶烷可以转化为相应的光学活性 1,3-二醇,它们是有价值的合成构件。
Immobilization of 3,5‐dimethylphenyl carbamate of cellulose and amylose on silica by photochemical and thermal radical processes
作者:Eric Francotte、Dan Huynh
DOI:10.1002/chir.23426
日期:2022.5
The immobilization of cellulose 3,5-dimethylphenyl carbamate and amylose 3,5-dimethylphenyl carbamate on silica gel carrier was achieved by using photochemical and thermal processes. Both approaches provide an easy access to materials which were applied as chiral stationary phases (CSPs) for the chromatographic resolution of racemic molecules.