Site- and Enantioselective Formation of Allene-Bearing Tertiary or Quaternary Carbon Stereogenic Centers through NHC–Cu-Catalyzed Allylic Substitution
作者:Byunghyuck Jung、Amir H. Hoveyda
DOI:10.1021/ja211269w
日期:2012.1.25
Catalyticenantioselective allylic substitutions that result in addition of an allenyl group (<2% propargyl addition) and formation of tertiary or quaternary C-C bonds are described. Commercially available allenylboronic acid pinacol ester is used. Reactions are promoted by a 5.0-10 mol % loading of sulfonate-bearing chiral bidentate N-heterocyclic carbene (NHC) complexes of copper, which exhibit the
NHC–Cu-Catalyzed Protoboration of Monosubstituted Allenes. Ligand-Controlled Site Selectivity, Application to Synthesis and Mechanism
作者:Fanke Meng、Byunghyuck Jung、Fredrik Haeffner、Amir H. Hoveyda
DOI:10.1021/ol4004178
日期:2013.3.15
Two types of NHC-Cu complexes catalyze protoborations of terminal allenes to afford valuable 1,1- or trisubstituted vinylboron species with high site selectivity and stereoselectivity. The scope of the method, application to natural product synthesis, and mechanistic basis for the observed selectivity trends are presented.
Organotin nucleophiles. 5. Palladium-catalyzed allylic propargylation with allenylstannane
作者:Ehud Keinan、Moshe Peretz
DOI:10.1021/jo00174a027
日期:1983.12
KEINAN, E.;PERETZ, M., J. ORG. CHEM., 1983, 48, N 26, 5302-5309