The borrowing-hydrogen (or hydrogen autotransfer) process, where the catalyst dehydrogenates a substrate and formally transfers the H atom to an unsaturated intermediate, is an atom-efficient and environmentally benign transformation. Described here is an example of an asymmetric borrowing-hydrogen cascade for the formal anti-Markovnikov hydroamination of allyl alcohols to synthesize optically enriched
Iridium/Brønsted acid cooperative catalyzed asymmetric allylicsubstitution reactions at the C5 position of indolines have been reported for the first time. The highly efficient protocol allows rapid access to various C5-allylated products in good to high yields (48–97%) and enantioselectivities (82% to >99% ee) with wide functional group tolerance. The transformations allow not only the formation
Iridium-Catalyzed Enantioselective Allylic Substitution with Aqueous Solutions of Nucleophiles
作者:Tobias Sandmeier、F. Wieland Goetzke、Simon Krautwald、Erick M. Carreira
DOI:10.1021/jacs.9b05830
日期:2019.8.7
The iridium-catalyzed asymmetric allylic substitution under biphasic conditions is reported. This approach allows the use of various unstable and/or volatile nucleophiles including hydrazines, methyl-amine, t-butyl hydroperoxide, N-hydroxylamine, α-chloroacetaldehyde and glutaraldehyde. This transformation pro-vides rapid access to a broad range of products from simple starting materials in good yields
报道了双相条件下铱催化的不对称烯丙基取代。这种方法允许使用各种不稳定和/或挥发性亲核试剂,包括肼、甲胺、叔丁基过氧化氢、N-羟胺、α-氯乙醛和戊二醛。这种转变提供了从简单的起始材料以良好的产率和高达 > 99% ee 和 20:1 dr 快速获得广泛产品的途径。此外,这些产品可以有效地加工成多种环状和非环状化合物,最多可带有四个立体中心。
Highly diastereo- and enantio-selective epoxidation of secondary allylic alcohols catalyzed by styrene monooxygenase
作者:Hui Lin、Yan Liu、Zhong-Liu Wu
DOI:10.1039/c0cc04360e
日期:——
Enantiomerically enriched glycidol derivatives with contiguous stereogenic centers were obtained in a highly diastereo- and enantio-selective epoxidation catalyzed with the styrene monooxygenase StyAB2.
We describe herein a palladium-catalyzed Heck-type reaction of O-acetyl ketoximes and allylicalcohols to pyridines. This protocol allows robust synthesis of pyridines and azafluorenones in good to excellent yields with...