for the preparation of 3-substituted isocoumarins via palladium-catalyzed nucleophilic addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective nucleophilic addition and C–H functionalization procedure.
Cu-catalyzed coupling-cyclization in PEG 400 under ultrasound: a highly selective and greener approach towards isocoumarins
作者:R. Gangadhara Chary、G. Rajeshwar Reddy、Y. S. S. Ganesh、K. Vara Prasad、S. K. Phani Chandra、Soumita Mukherjee、Manojit Pal
DOI:10.1039/c3ra40969d
日期:——
The combination of CuI–K2CO3-PEG 400 facilitated the coupling-cyclization of o-iodobenzoic acid with terminal alkynes under ultrasound, affording a greener and practical approach towards 3-substituted isocoumarins with remarkable regioselectivity. This inexpensive and Pd and ligand free methodology gave rise to various isocoumarins of potential pharmacological interest.