Highly Activated Vinyl Hydrogen in a Significantly Twisted Styrene
摘要:
The novel example of a vinylic hydrogen more reactive than a benzylic hydrogen was found by treatment of a twisted styrene derivative with a strong base followed by D2O quenching. In this paper, the full details of the examples of the highly activated vinyl hydrogens in twisted styrene derivatives are described, with a discussion on the correlation between the reactivity of the vinyl hydrogens and the magnitude of the twist. The highly reactive vinyl hydrogens could be rationalized by considering the novel orbital interaction between the pi* orbital of the benzene ring and the sigma orbital of the vinylic C-H bond in the twisted styrene derivatives.
Highly Activated Vinyl Hydrogen in a Significantly Twisted Styrene
摘要:
The novel example of a vinylic hydrogen more reactive than a benzylic hydrogen was found by treatment of a twisted styrene derivative with a strong base followed by D2O quenching. In this paper, the full details of the examples of the highly activated vinyl hydrogens in twisted styrene derivatives are described, with a discussion on the correlation between the reactivity of the vinyl hydrogens and the magnitude of the twist. The highly reactive vinyl hydrogens could be rationalized by considering the novel orbital interaction between the pi* orbital of the benzene ring and the sigma orbital of the vinylic C-H bond in the twisted styrene derivatives.
Copper and neocuproine catalysed synthesis of cinnamyl ether derivatives directly from secondary and tertiary cinnamyl alcohols
作者:Zhenjiao Yang、Yongsheng Zhang、Xingxian Lv、Yang Yang、Chunhao Jiang、Xiaoyan He、Guoliang Chen、Gang Huang、Xiuhong Lu
DOI:10.1039/d2gc01602h
日期:——
The skeletons of secondary and tertiary cinnamyl alcohols are found ubiquitously in natural products and commercial drugs. Due to the easy dehydration of their structures, the etherification of such compounds is often difficult. A new method for the synthesis of secondary and tertiary cinnamyl ether derivatives, employing copper sulfate pentahydrate (CuSO4·5H2O) as a catalyst and neocuproine as a ligand
The 1,3-rearrangement of allylic derivatives has rarely been reported, except for allylic alcohols. Herein, we describe an iridium-catalyzed 1,3-rearrangement of readily available allylic ethers to access the difficultly prepared allylic ethers with a large steric hindrance. The developed method shows a broad substrate scope and could be used in the late-stage modification of several natural products
The novel example of vinyl hydrogen more reactive than benzylic hydrogen was found by treatment of a twisted styrene derivative with a strong base followed by D2O quenching. The characteristic nature of the vinyl hydrogen, which is activated by sigma-pi* orbital interaction, was apparently demonstrated. (C) 2001 Elsevier Science Ltd. All rights reserved.