Facile synthesis of 4H-naphtho[2,3-e] derivatives of 1,3-thiazines and 1,3-selenazines and naphtho[2',3':4,5] derivatives of selenolo[2,3-b]pyridines and thieno[2,3-b]pyridines via 2,3-didehydronaphthalene

Abstract

The required (phenyl)[(3-trimethylsilyl)-2-naphthyl]iodonium triflate (3) was prepared from 2,3-dibromonaphthalene. 13 The thiaazabutadienes (2a-e) 14 and the selenoazadienes (6a-f) 15 were prepared by literature procedures. With the exception of thiaazadiene (2e) the thiaazadienes (2a-d) are new compounds and their % yields are shown in Scheme 1. The Barton selenium esters (8a-e) were prepared from 2-chloropyridines 12 and the Barton sulfur esters (10a-d) were prepared by the Barton method.