Improving Sustainability in Ene-Yne Cross-Metathesis for Transformation of Unsaturated Fatty Esters
作者:Virginie Le Ravalec、Antoine Dupé、Cédric Fischmeister、Christian Bruneau
DOI:10.1002/cssc.201000212
日期:2010.11.22
ene–yne cross‐metathesis is performed with stoichiometric proportions of terminal olefins and alkynes. This is made possible by the continuous addition of the alkyne to the reaction mixture. The protocol allows the ene–yne cross‐metathesis reaction to be carried out with long‐chain terminal olefins and in a one‐pot fashion with internal olefins after shortening by ethenolysis. The efficient conversion
One-Pot Synthesis of a Variety of 1,4-Alkadienes and 1,2,4-Alkatrienes from Alkynes, Allyl, or Propargyl Compounds and Electrophiles by a (η2-Propene)Ti(O-i-Pr)2-Mediated Reaction
作者:Sentaro Okamoto、Yuuki Takayama、Yuan Gao、Fumi Sato
DOI:10.1055/s-2000-6296
日期:——
The intermolecular reaction of alkynes with allyl or propargyl compounds mediated by (η2-propene)Ti(O-i-Pr)2 followed by trapping of the resulting vinyltitanium compounds with an electrophile such as H2O, I2 or an aldehyde furnished a variety of 1,4-alkadienes or 1,2,4-alkatrienes.
Enantioselective, Stereodivergent Hydroazidation and Hydroamination of Allenes Catalyzed by Acyclic Diaminocarbene (ADC) Gold(I) Complexes
作者:Dimitri A. Khrakovsky、Chuanzhou Tao、Miles W. Johnson、Richard T. Thornbury、Sophia L. Shevick、F. Dean Toste
DOI:10.1002/anie.201601550
日期:2016.5.10
The gold‐catalyzed enantioselective hydroazidation and hydroamination reactions of allenes are presented herein. ADC gold(I) catalysts derived from BINAM were critical for achieving high levels of enantioselectivity in both transformations. The sense of enantioinduction is reversed for the two different nucleophiles, allowing access to both enantiomers of the corresponding allylic amines using the
powerful synthetic strategies for making new substances that have been of significant importance in chemistry, medicine, and material fields. Conventional tactics employ various preformed allylation and propargylation reagents. In this study, a conceptually novel copper-catalyzed and B2pin2-mediated Umpolung reactivity of propargylic carbonates has been achieved for the first time, realizing both allylation
First Transformation of Unsaturated Fatty Esters Involving Enyne Cross-Metathesis
作者:Virginie Le Ravalec、Cédric Fischmeister、Christian Bruneau
DOI:10.1002/adsc.200800726
日期:2009.5
Abstractmagnified imageThe ruthenium‐catalysed enyne cross‐metathesis of several alkyne derivatives with terminal olefins was performed. These reactions were efficiently achieved under mild conditions in dimethyl carbonate, an eco‐friendly solvent. A unique one‐pot reaction based on an ethenolysis step followed by an enyne cross‐metathesis allowed the efficient transformation of renewable unsaturated fatty esters into valuable conjugated 1,3‐dienes of interest for further transformations.