An enantioselective oxidative carbocyclization–borylation of enallenes that is catalyzed by palladium(II) and a Brønsted acid was developed. Biphenol‐type chiral phosphoric acids were superior co‐catalysts for inducing the enantioselective cyclization. A number of chiral borylated carbocycles were synthesized in high enantiomeric excess.
Palladium-Catalyzed Oxidative Domino Carbocyclization–Carbonylation–Alkynylation of Enallenes
作者:Chandra M. R. Volla、Jan-E. Bäckvall
DOI:10.1021/ol501862z
日期:2014.8.15
An oxidative carbocyclization–carbonylation–alkynylation reaction cascade has been developed using catalytic amounts of palladium(II) salts. The domino reaction proceeds efficiently, giving the corresponding ynones in good to excellent yields under operationally simple conditions. A wide range of aromatic and aliphatic terminal alkynes with various functional groups are tolerated under the reaction
Palladium‐Catalyzed Oxidative Carbocyclization–Carbonylation of Allenynes and Enallenes
作者:Chandra M. R. Volla、Javier Mazuela、Jan‐E. Bäckvall
DOI:10.1002/chem.201402688
日期:2014.6.16
A highly efficient oxidativecarbocyclization–carbonylation reaction cascade of allenynes and enallenes has been developed using a PdII salt in low catalytic amounts under ambient temperature and pressure (1 atm of carbon monoxide). The use of DMSO as an additive was found to be important for an efficient reaction. A wide range of alcohols as trapping reagents were used to give the corresponding esters