Water-Accelerated Nickel-Catalyzed α-Crotylation of Simple Ketones with 1,3-Butadiene under pH and Redox-Neutral Conditions
摘要:
We report a nickel/NHC-catalyzed branched-selective acrotylation of simple ketones using 1,3-butadiene as the alkylation agent. This reaction is regioselective and operated under pH and redox-neutral conditions. Water was used as the sole additive, which significantly accelerates the transformation.
Ni(acac)(2) catalyzes homoallylation of aldehydes with 1,3-dienes in the presence of triethylborane. Triethylborane serves as a reducing agent delivering a formal hydride to the C2 position of 1,3-dienes, thus generating a formal homoallyl anion species and enabling the novelhomoallylation of aldehydes. The reaction proceeds smoothly at room temperature in the absence of any phosphane or nitrogen
A Formal Synthesis of the C1−C9 Fragment of Amphidinolide C Employing the Tamaru Reaction
作者:Mahesh P. Paudyal、Nigam P. Rath、Christopher D. Spilling
DOI:10.1021/ol100959a
日期:2010.7.2
Homoallylation of aldehydes with isoprene and triethylborane catalyzed by Ni(acac)2 gave hydroxyalkenes in good yield with excellent regio- and stereoselectivity. Cross metathesis of the hydroxyalkenes with methyl acrylate using second-generation Grubbs catalyst and copper(I) iodide afforded α,β-unsaturated esters, which underwent cyclization in the presence of DBU to produce tetrahydrofurans with