PALLADIUM ASSISTED ORGANIC REACTIONS. IV. A NEW ISOQUINOLINE RING SYNTHESIS

Article abstract of DOI:10.1016/S0022-328X(00)99234-9

Ethyl N-methyl-N-(3,4-methylenedioxy)benzylglycinate is cyclopalladated regiospecifically at C(6) when treated with Li2PdCl4.The di-μ-chloro-bis(N,N-dialkylbenzylamine-6-C,N)dipalladium(II) complex that results undergoes an insertion reaction with methyl vinyl ketone, and the resultant β-aryl-α,β-unsaturated ketone is cyclised, as the methiodide, by K2CO3 in ethanol to the corresponding ethyl N,N-dimethyl-1,2,3,4-tetrahydroisoquinolinium-3-carboxylate.This sequence constitutes a new synthesis of the isoquinoline ring, with functionalised substituents at C(3) and C(4).