Cooperativity of Regiochemistry Control Strategies in Reductive Couplings of Propargyl Alcohols and Aldehydes
摘要:
The nickel-catalyzed reductive coupling of propargyl alcohols and alkynes proceeds with excellent regiochemical control with an underlying electronic preference that can be supplemented by ligand size effects. The products obtained may be readily converted to substructures that are not directly available by an aldehyde-alkyne reductive coupling. A simple model for how steric and electronic factors are both important in governing regiochemistry in couplings of this type is presented, along with examples of how the effects can combine in either a constructive or destructive manner.
A General Strategy for Regiocontrol in Nickel-Catalyzed Reductive Couplings of Aldehydes and Alkynes
作者:Hasnain A. Malik、Grant J. Sormunen、John Montgomery
DOI:10.1021/ja102262v
日期:2010.5.12
a broad range of couplings, without relying on substrate biases or directing effects. The complementary use of small cyclopropenylidene carbene ligands or highly hindered N-heterocyclic carbene ligands allows the regiochemical reversal with unbiased internal alkynes, aromatic internal alkynes, conjugatedenynes, or terminalalkynes.
Cooperativity of Regiochemistry Control Strategies in Reductive Couplings of Propargyl Alcohols and Aldehydes
作者:Hasnain A. Malik、Mani Raj Chaulagain、John Montgomery
DOI:10.1021/ol902561r
日期:2009.12.17
The nickel-catalyzed reductive coupling of propargyl alcohols and alkynes proceeds with excellent regiochemical control with an underlying electronic preference that can be supplemented by ligand size effects. The products obtained may be readily converted to substructures that are not directly available by an aldehyde-alkyne reductive coupling. A simple model for how steric and electronic factors are both important in governing regiochemistry in couplings of this type is presented, along with examples of how the effects can combine in either a constructive or destructive manner.