General and Efficient Indole Syntheses Based on Catalytic Amination Reactions
作者:Lutz Ackermann
DOI:10.1021/ol047649j
日期:2005.2.1
Highly flexible and efficient syntheses of the indole backbone are presented starting from o-alkynylhaloarenes. These transformations proceed via a palladium- or a copper-catalyzed amination reaction and a subsequent cyclization reaction in good to excellent yields. Furthermore. a multicatalytic one-pot indole synthesis starting from o-chloroiodobenzene is viable using a single catalyst consisting of an N-heterocyclic carbene palladium complex and Cul.
2,3-Disubstituted Benzofuran and Indole by Copper-Mediated C−C Bond Extension Reaction of 3-Zinciobenzoheterole
[reaction: see text] A metalative 5-endo-dig cyclization reaction of 2-ynylphenoles or anilines effected by BuLi and ZnCl(2) produces 3-zinciobenzoheteroles in excellent yield. These intermediates have been transmetalated to the corresponding cuprates and allowed to react with electrophiles to produce a variety of 2,3-disubstituted benzofurans and indoles.