这项工作展示了一种新的催化环化反应,该反应使用高度路易斯酸的硼烷并伴有CH或CC键的形成。用B(C 6 F 5)3活化含炔的底物使得能够使用该路易斯酸对羧酸底物进行第一个催化的分子内环化反应。此外,酯的分子内环化使CC键形成为催化性B(C 6 F 5)3。可用于实现从酯官能团到不饱和碳-碳骨架的正式1,5-烷基迁移。该无金属方法用于在相对温和的条件下以极高的收率和极好的原子效率催化形成复杂的二氢吡喃酮和异香豆素。
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
The EtAlCl2-mediated intramolecular addition of silyl enol ethers to both terminal and internal unactivatedalkynes, bearing alkyl and phenyl susbstituents at the alkyne moiety, gave mono- and bicyclic β,γ-unsaturated ketones in good to excellent yields. On the other hand, the silyloxy-substituted cyclic vinylsilanes were obtained in moderate to high yields when the reactions were catalyzed by B(C6F5)3
Bismuth-Catalyzed Intramolecular Carbo-oxycarbonylation of 3-Alkynyl Esters
作者:Kimihiro Komeyama、Keita Takahashi、Ken Takaki
DOI:10.1021/ol8019567
日期:2008.11.20
Borderline metal complexes, especially Bi(OTf)3, efficiently catalyze the carbo-oxycarbonylation of alkynyl esters to form multisubstituted lactones in moderate to high yields.