In this work, for the first time, task‐specific ionic liquid, 1‐n‐butyl‐3‐methylimidazolium borohydride ([bmim]BH4), was used as the medium as well as reagent for the regiospecific reduction of triarylpyrylium perchlorates to provide aromatic dienones as only product. The [bmim]BH4 having a reactive anion also could promote the desired reaction thereby reducing the reaction times and improving the
Δ3-Dihydropyrans and tetrahydropyrans by reduction of pyrylium salts with sodium borohydride in acetic acid
作者:Teodor-Silviu Balaban、Alexandru T Balaban
DOI:10.1016/s0040-4039(00)95365-6
日期:1987.1
major reduction products with triacetoxyborohydride (NaBH4 in AcOH) of 2,4,6-trisubstituted pyrylium salts bearing alkyl substituents in the 2- and/or 6- position are the Δ3-dihydropyrans with 2- and 6- substituents and the all--2,4,6-trisubstituted tetrahydropyrans. Δ3-Dihydropyrans are shown to be formed 2H-pyrans by a 1,4 reduction while tetrahydropyrans result from 4H-pyrans by reduction of both
Substituent effects in reductions of heteroaromatic cations
作者:David Heyes、Ramesh S. Menon、C. Ian. F. Watt、Jake Wiseman、Przemyslaw Kubinski
DOI:10.1002/poc.532
日期:2002.10
structural features in the cations, radicals and anions in each series. Rates and products were determined for reductions of the pyrylium and thiopyrylium cations by sodium cyanoborohydride and of all cations by sodium borohydride in acetonitrile solution. Reactions are first order in reducing agent and cation. Primary kinetic isotope effects were determined for borohydridereduction of the least reactive
Compositions and methods for visible-light-controlled ruthenium-catalyzed olefin metathesis
申请人:The Trustees of Columbia University In The City of New York
公开号:US11331656B2
公开(公告)日:2022-05-17
The present disclosure provides compositions and methods for metathesizing a first alkenyl or alkynyl group with a second alkenyl or alkynyl group, the composition comprising a ruthenium metathesis catalyst and a photoredox catalyst that is activated by visible light.