Gold Catalysis: Synthesis of 3-Acylindenes from 2-Alkynylaryl Epoxides
作者:A. Stephen K. Hashmi、Miriam Bührle、Ralph Salathé、Jan W. Bats
DOI:10.1002/adsc.200800385
日期:2008.9.5
A series of 2-alkynylarylepoxides were prepared by a sequence of Sonogashira coupling, Wittig olefination and epoxidation or a Darzens’ glycid ester synthesis. The conversion of these substrates with gold(I) catalysts furnished 3-acylindenes and, in occasional cases as side-products, the products of an isomerization of the oxirane ring to a ketone. Isotope labelling of the epoxide oxygen indicates
Palladium(0)‐Catalyzed
<i>Anti</i>
‐Selective Addition‐Cyclizations of Alkynyl Electrophiles
作者:Hirokazu Tsukamoto、Kazuya Ito、Tatsuhiko Ueno、Mitsugu Shiraishi、Yoshinori Kondo、Takayuki Doi
DOI:10.1002/chem.202203068
日期:2023.1.27
Palladium(0)/monophosphine complexes catalyze anti-selective arylative cyclizations of alkynyl electrophiles with organometallic reagents. Remarkably, the regioselectivity in the cyclization of conjugated diyne-aldehydes can be controlled by a choice of the phosphine ligand, with triphenylphosphine and tricyclohexylphosphine leading to the exclusive formation of 2-alkylidene-cyclopentanol and 2-cyclohexen-1-ol
trifluoromethoxylation with only two successful reports since the first discovery. Here, by subtly tuning the leaving group, protecting group, ligand structure, reactiontemperature, solvent and base, we finally realized a copper-catalyzed enantioselective trifluoromethoxylation of propargyl sulfonates for the first time.