Engaging Alkenyl Halides with Alkylsilicates via Photoredox Dual Catalysis
作者:Niki R. Patel、Christopher B. Kelly、Matthieu Jouffroy、Gary A. Molander
DOI:10.1021/acs.orglett.6b00024
日期:2016.2.19
Single-electron transmetalation via photoredox/nickel dual catalysis provides the opportunity for the construction of Csp3–Csp2 bonds through the transfer of alkyl radicals under very mild reaction conditions. A general procedure for the cross-coupling of primary and secondary (bis-catecholato)alkylsilicates with alkenyl halides is presented. The developed method allows not only alkenyl bromides and
Metal free photooxidation of alkyl bis(catecholato)silicates with the organic dye, 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyano-benzene (4CzIPN), allows the smooth formation of alkyl radicals. The latter can be efficiently engaged either with radical acceptors to...
Increased Efficiency in Cross-Metathesis Reactions of Sterically Hindered Olefins
作者:Ian C. Stewart、Christopher J. Douglas、Robert H. Grubbs
DOI:10.1021/ol702624n
日期:2008.2.1
Efficiency in olefin cross-metathesis reactions is affected upon reducing the steric bulk of N-heterocyclic carbene ligands of ruthenium-based catalysts. For the formation of disubstituted olefins containing one or more allylic substituents, the catalyst bearing N-tolyl groups is more efficient than the corresponding N-mesityl catalyst. In contrast, the formation of trisubstituted olefins is more efficient
High conversions in ruthenium-based olefinmetathesis of demanding substrates are commonly forced by using a high loading of a catalyst and conducting reactions at elevated temperature for extended times. However, in many cases this approach is not fully effective. In this article we present that fluorinated aromatic hydrocarbons (FAH) combined with microwave (MW) irradiation using a commercially available