We report here a Ni-catalyzed reductive coupling of aldehydes with widely available 1,3-dienes under visible-light photoredox dualcatalysis. The homoallyic alcohols are obtained in broad scope with complete branched regioselectivity. Hantzsch ester is used as the hydrogen radical source to oxidize low-valent nickel salt affording Ni–H species. Preliminary mechanistic studies indicate a successive
The Employment of Indium Nanoparticles in Barbier-type Reaction of Allylic Chloride in Water
作者:Jiaming Li、Zhenggen Zha、Lilin Sun、Yan Zhang、Zhiyong Wang
DOI:10.1246/cl.2006.498
日期:2006.5
Indium nanoparticles have been employed in the reactions of various carbonyl compounds with allyl (crotyl) chloride in water, affording the corresponding alcohols with high yields. The crotylation gave exclusive γ-adducts with a dominant syn-isomer.
nBu4NBr/PbI2 acts as an effective catalyst for the allylation of aldehydes 2 with the allylic tin reagents 1 in water. A high syn-selectivity of 3 was achieved in water without any aprotic solvents in the reaction of the aromatic aldehydes 2 with the crotyltri-n-butyltin reagents 1b, 1c irrespective of their E/Z geometry.