Palladium-catalysed direct cross-coupling of secondary alkyllithium reagents
作者:Carlos Vila、Massimo Giannerini、Valentín Hornillos、Martín Fañanás-Mastral、Ben L. Feringa
DOI:10.1039/c3sc53047g
日期:——
Palladium-catalysed cross-coupling of secondary C(sp3) organometallic reagents has been a long-standing challenge in organic synthesis, due to the problems associated with undesired isomerisation or the formation of reduction products. Based on our recently developed catalytic C–C bond formation with organolithium reagents, herein we present a Pd-catalysed cross-coupling of secondary alkyllithium reagents with aryl and alkenyl bromides. The reaction proceeds at room temperature and on short timescales with high selectivity and yields. This methodology is also applicable to hindered aryl bromides, which are a major challenge in the field of metal catalysed cross-coupling reactions.
Bulky P,PO ligands were designed to inhibit isomerization and reduction side reactions during the crosscoupling between sterically hindered aryl halides and alkylboronic acids. Suzuki–Miyaura cross‐couplings between di‐ortho‐substituted aryl bromides and acyclic secondary alkylboronic acids have been achieved with high yields. The method has also enabled the preparation of ortho‐alkoxy di‐ortho‐substituted
Stereoselective Diels−Alder Reactions of Chiral Anthracenes
作者:Amitav Sanyal、John K. Snyder
DOI:10.1021/ol006206m
日期:2000.8.1
Various chiral (9-anthryl)carbinol templates undergo Diels-Alder cycloadditions with a variety of symmetric and nonsymmetric dienophiles with excellent pi-facial selectivity and regioselectivity, under both thermal and Lewisacidcatalyzedconditions.