Copper-Catalyzed Alkene Aminoazidation as a Rapid Entry to 1,2-Diamines and Installation of an Azide Reporter onto Azahetereocycles
作者:Kun Shen、Qiu Wang
DOI:10.1021/jacs.7b06852
日期:2017.9.20
A copper-catalyzed aminoazidation of unactivated alkenes is achieved for the synthesis of versatile unsymmetrical 1,2-diamine derivatives. This transformation offers an effective approach to installing an amide and an azide from two diffenent amino precursors onto both terminal and internal alkenes, with remarkable regio- and stereoselectivity. Mechanistic studies show that this diamination reaction
Transition-metal catalyzed synthesis of δ-hydroxy-γ-lactones from bis(trimethylsilyl) ketene acetals and allylic acetates via γ-unsaturated carboxylic acids. Comments on the formation of α-cyclopropyl carboxylic acids
Bis(trimethylsilyl)keteneacetals react with allylic acetates in the presence of Pd(0) complexes to give γ-unsaturated carboxylic acids together with α-cyclopropyl carboxylic acids. The unsaturated acids can be converted catalytically to δ-hydroxy-γ-lactones by the H2O2/MTO system (methyltrioxorhenium) and to butenolides by Pd(II) catalyzed intramolecular cyclization reactions. The structure of two
双(三甲基甲硅烷基)乙烯酮缩醛在Pd(0)配合物的存在下与乙酸烯丙酯反应生成γ-不饱和羧酸与α-环丙基羧酸。H 2 O 2 / MTO系统(甲基三氧or)可将不饱和酸催化转化为δ-羟基-γ-内酯,而Pd(II)催化的分子内环化反应则可将其转化为丁烯化物。这些内酯中的两个的结构已经通过X射线分析确定。将讨论环丙酸的形成机理。
Reversing the Regioselectivity of Halofunctionalization Reactions through Cooperative Photoredox and Copper Catalysis
作者:Jeremy D. Griffin、Cortney L. Cavanaugh、David A. Nicewicz
DOI:10.1002/anie.201610722
日期:2017.2.13
Halofunctionalization of alkenes is a classical method for olefin difunctionalization. It gives rise to adducts which are found in many natural products and biologically active molecules, and offers a synthetic handle for further manipulation. Classically, this reaction is performed with an electrophilic halogen source and leads to regioselective formation of the halofunctionalized adducts. Herein
Bis(trimethylsilyl) ketene acetals react successively with
allylic acetates, in the presence of Pd(0) then with
H2O2, in the presence of methyltrioxorhenium, to give
δ-hydroxy-γ-lactones via γ-unsaturated
carboxylic acids.
Mechanism of Oxygen Transfer in the Epoxidation of an Olefin by Molecular Oxygen in the Presence of an Aldehyde
作者:Stephen G. Jarboe、Peter Beak
DOI:10.1021/ol991304x
日期:2000.2.1
see text] The reaction pathway for peroxide-initiated aldehyde-mediated oxidation of olefins to epoxides by molecular oxygen has been studied. The pathways of reaction via a peroxyacid or an acyl peroxy radical have been differentiated by investigation of the reaction of 4 with oxygen to provide 6 via 8.