Substrate-controlled divergent synthesis with ortho-vinyl-functionalised 1,3-enynes and imines via palladium catalysis

Abstract

Presented herein is a substrate-controlled diversity-oriented approach to access skeletally different frameworks from ortho-vinyl-functionalised 1,3-enynes and imines via palladium catalysis. A variety of benzofulvenes were constructed in moderate to high yields, enantioselectivity and E-selectivity, through a cascade vinylogous addition, 5-exo-trig migratory insertion and β-H elimination process. In addition, modifing the vinyl substitutions of 1,3-enyne substrates could switch the Oppolzer cyclisation into a 6-endo-trig pattern, which finally furnished formal 1-naphthylated amines enantioselectively under similar conditions. Moreover, the 2-furyl imine-derived naphthalene products further underwent a domino intramolecular Diels–Alder cycloaddition reaction, furnishing complex oxabicyclo[2.2.1]heptane architectures. The efficient construction of distinctly structured libraries exhibited well the versatility of the current substrate-controlled strategy.