Rh(I) catalyzes the reductive coupling reaction of a wide variety of aldehydes with conjugateddienes in the presence of a stoichiometric amount of triethylborane to provide homoallyl alcohols in a single operation.
In this study, the Bu2SnIH-catalyzed direct coupling of 1,3-dienes with aldehydes was developed. This reaction could be suitable for coupling without the use of transition-metal catalysts. Many types of aldehydes were applied to this reaction. The addition of MeOH promoted the catalytic cycle.
Allylic indiums, generated by a conjugate hydroindation of 1,3-dienes by HInCl2, reacted with carbonyl compounds in a one-pot treatment. Both γ- and α-adducts can be obtained depending upon the conditions used.
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
Generation of Allylic Indium by Hydroindation of 1,3-Dienes and One-Pot Reaction with Carbonyl Compounds
作者:Naoki Hayashi、Hiroyuki Honda、Makoto Yasuda、Ikuya Shibata、Akio Baba
DOI:10.1021/ol061797n
日期:2006.9.1
A hydroindation of 1,3-dienes by dichloroindium hydride (HInCl2) generates allylic indiums that react with carbonyl or imine moieties in a one-pot treatment. The former reaction proceeds in a radical manner, and the latter is ionic allylation. Moreover, both reactions require no additives such as radical initiators, Lewis acids, or transition metal catalysts.