A Convenient Solid-Phase Synthesis of Coumarins by TMSOTf-Catalyzed Intramolecular Seleno-Arylation of Tethered Alkenes
作者:E. Tang、Wen Li、Zhangyong Gao
DOI:10.1055/s-0031-1290618
日期:2012.4
performed using polystyrene-supported succinimidyl selenide as the selenium source. This catalytic process provides an efficient method for the regioselectivesynthesis of dihydrocoumarins possessing a seleno functionality, followed by syn elimination of selenoxides to provide coumarins in good yields and purities. Suzuki cross-coupling reaction of the resin-bound bromodihydrocoumarin was also performed
Nickel(0)-Catalyzed Enantioselective Annulations of Alkynes and Arylenoates Enabled by a Chiral NHC Ligand: Efficient Access to Cyclopentenones
作者:Joachim S. E. Ahlin、Pavel A. Donets、Nicolai Cramer
DOI:10.1002/anie.201408364
日期:2014.11.24
nickel‐catalyzed reductive [3+2] cycloaddition of α,β‐unsaturated aromatic esters and alkynes constitutes an efficient method for their synthesis. Here, nickel(0) catalysts comprising a chiral bulky C1‐symmetric N‐heterocyclic carbene ligand were shown to enable an efficient asymmetric synthesis of cyclopentenones from mesityl enoates and internal alkynes under mild conditions. The bulky NHC ligand