Stereoselective construction of vicinal diamines. Part 1. Synthesis of fused pyrazines

Abstract

A stereoselective approach to the construction of trans-1, 2-diaminoindanes 8a, b and trans-1,2-diaminotetralins 9a, b is described. The trans-adducts 4 and 5, derived from the addition of N, N dichlorourethane to indene and 1,2-dihydronaphthalene, react with aryl amines to give trans-diamines 8a, b and 9a, bvia the protonated oxazoline intermediates 13 and 14. Elaboration of vicinal diamines 8a, b and 9a, b affords the diazabenzocycloheptafluorene 2 and dibenzopyrazinobenzazepine 3, respectively.