Cross Enyne Metathesis of <i>para</i>-Substituted Styrenes: A Kinetic Study of Enyne Metathesis
作者:Anthony J. Giessert、Steven T. Diver
DOI:10.1021/ol047533n
日期:2005.1.1
[Reaction: see text] The intermolecular enyne metathesis between alkynes and styrene derivatives was developed to study electronic effects in enyne metathesis. A Hammett plot for the overall reaction, catalyst initiation and vinyl carbene turnover was determined with the second generation Grubbs ruthenium carbene catalyst.
Tandem Cycloaddition Reactions of Allenyl Diazo Compounds Forming Triquinanes via Trimethylenemethane Diyls
作者:Taek Kang、Won-Yeob Kim、Yeokwon Yoon、Byung Gyu Kim、Hee-Yoon Lee
DOI:10.1021/ja207591e
日期:2011.11.16
A tandem reaction strategy for forming triquinanes from linear allenyl diazo compounds through an intramolecular 1,3-dipolar cycloadditionreaction of an allenyl diazo group that generates a trimethylenemethane (TMM) diyl followed by an intramolecular [2 + 3] TMMdiylcycloadditionreaction has been developed. The new tandem cycloadditionreaction is readily applicable to the synthesis of complex molecules
Acetonyltriphenylphosphonium Bromide (ATPB): A Versatile Reagent for the Acylation of Alcohols, Phenols, Thiols and Amines and for 1,1-Diacylation of Aldehydes under Solvent-Free Conditions
作者:Abu T. Khan、Lokman H. Choudhury、Subrata Ghosh
DOI:10.1002/ejoc.200500066
日期:2005.7
A wide variety of alcohols, phenols, amines and thiols may easily be converted into the corresponding acetate derivatives by treatment with acetic anhydride (1.5–2.0 equivalents) in the presence of acetonyltriphenylphosphonium bromide (ATPB; 5 mol %) in good yields at room temperature. With the same precatalyst, both aliphatic and aromatic aldehydes can also be transformed into the corresponding gem-diacetates
A rhodium‐catalyzed asymmetricsynthesis of silicon‐stereogenic dibenzosiloles has been developed through a [2+2+2] cycloaddition of silicon‐containing prochiral triynes with internal alkynes. High yields and enantioselectivities have been achieved by employing an axially chiral monophosphine ligand, and the present catalysis is also applicable to the asymmetricsynthesis of a germanium‐stereogenic
Ruthenium-Catalyzed [2+2+2] Cycloaddition of 1,6-Enynes and Unactivated Alkynes: Access to Ring-Fused Cyclohexadienes
作者:Rui Liu、Laurent Giordano、Alphonse Tenaglia
DOI:10.1002/asia.201700642
日期:2017.9.5
The [2+2+2] intermolecular carbocyclization reactions between 1,6‐enynes and alkynes catalyzed by [RuCl(cod)(Cp*)] (cod=1,5‐cyclooctadiene, Cp*=pentamethylcyclopentadienyl) are reported to provide bicyclohexa‐1,3‐dienes. The presented reaction conditions are compatible with internal and terminal alkynes and the chemo‐ and regioselectivity issues are controlled by the presence of substituents at the