Benzotriazole-Mediated [2,3]-Wittig Rearrangement. General and Stereocontrolled Syntheses of Homoallyl Alcohols and β,γ-Unsaturated Ketones
作者:Alan R. Katritzky、Hong Wu、Linghong Xie
DOI:10.1021/jo960019d
日期:1996.1.1
give secondary and tertiary homoallyl alcohols (16 and 21), respectively, exclusively in the E configuration in excellent yields. This is achieved by deprotonation followed by [2,3]-Wittig rearrangement, departure of the benzotriazolyl group, and then nucleophilic addition to the resulting carbonyl compound. Following a similar protocol, primary E-homoallyl alcohols 18 are prepared in good yield by the
Photocatalytic Barbier reaction – visible-light induced allylation and benzylation of aldehydes and ketones
作者:Anna Lucia Berger、Karsten Donabauer、Burkhard König
DOI:10.1039/c8sc02038h
日期:——
We report a photocatalytic version of the Barbier type reaction using readily available allyl or benzyl bromides and aromatic aldehydes or ketones as starting materials to generate allylic or benzylic alcohols. The reaction proceeds at room temperature under visible light irradiation with the organic dye 3,7-di(4-biphenyl)1-naphthalene-10-phenoxazine as a photocatalyst and DIPEA as sacrificial electron
Irradiation of aromatic carbonylcompounds and allyl-, 2-methyl-2-propenyl-, or 3-methyl-2-butenyltrimethylstannanes in acetonitrile afforded δ,γ-unsaturated alcohols as major product. A photoinduced electron transfer mechanism is proposed for the allylations.