A copper(I)‐catalyzed addition of alkylborane reagents to α‐iminoacetates has been developed to assemble both acyclic and cyclic α‐branched α‐amino carboxylic acid derivatives in good yields. A wide variety of unactivated alkenes are well tolerated in this transformation.
Enantioselective Conjugate Addition of Alkylboranes Catalyzed by a Copper–<i>N</i>-Heterocyclic Carbene Complex
作者:Mika Yoshida、Hirohisa Ohmiya、Masaya Sawamura
DOI:10.1021/ja304481a
日期:2012.7.25
The first catalytic enantioselective conjugate addition of alkylboron compounds has been achieved. Reactions between alkylboranes and imidazol-2-yl α,β-unsaturated ketones proceeded with high enantioselectivity under the influence of a Cu(I) catalyst system, prepared in situ from CuCl, a new chiral imidazolium salt as a precursor for the N-heterocyclic carbene ligand, and PhOK. Alkylboranes are widely
Copper-Catalyzed Conjugate Additions of Alkylboranes to Imidazolyl α,β-Unsaturated Ketones: Formal Reductive Conjugate Addition of Terminal Alkenes
作者:Hirohisa Ohmiya、Mika Yoshida、Masaya Sawamura
DOI:10.1021/ol102819k
日期:2011.2.4
Conjugateaddition of alkylboron compounds (alkyl-9-BBN) to imidazol-2-yl α,β-unsaturated ketones proceeded in the presence of a catalytic amount (10 mol %) of CuCl, 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes), and t-BuOK. The alkylboranes are available through alkene hydroboration, and thus the overall process represents a reductive conjugateaddition of alkenes to enone derivatives. A
Asymmetric Synthesis of Dihydropyranones via Gold(I)‐Catalyzed Intermolecular [4+2] Annulation of Propiolates and Alkenes
作者:Hanbyul Kim、Su Yeon Choi、Seunghoon Shin
DOI:10.1002/anie.201807514
日期:2018.10
Intermolecular asymmetric gold catalysis involving alkyne activation presents a significant challenge due to its distinct mechanistic mode from other metals. Herein, we report a highly enantioselective synthesis of α,β‐unsaturated δ‐lactones from [4+2] annulation of propiolates and alkenes in upto 95 % ee. Notably, for the desired chiral recognition, the choice of 1,1,2,2‐tetrachloroethane as solvent
The copper-catalysed Suzuki–Miyaura coupling of alkylboron reagents: disproportionation of anionic (alkyl)(alkoxy)borates to anionic dialkylborates prior to transmetalation
作者:Prakash Basnet、Surendra Thapa、Diane A. Dickie、Ramesh Giri
DOI:10.1039/c6cc05114f
日期:——
A novel Cu-catalyzed Suzuki–Miyaura cross-coupling of alkylboron reagents with aryl and heteroaryl iodides is reported.