名称:
Studies on chalcogen-containing heterocycles. Part 38: Regio- and stereoselective tandem addition–iodocyclization of 2-ethynylphenyl isothiocyanates with N- and O-nucleophiles affording 4-(iodoalkylidene)benzo[d][1,3]thiazines
摘要:
The treatment of the o-ethynylphenyl isothiocyanates with primary and secondary amines in 1,2-DCE, followed by the addition of 12 and then heating resulted in the regio- and stereoselective tandem addition-iodocyclization to give the (4E)-2-amino-4-(1-iodomethylidene)benzo[d][1,3]thiazine derivatives as the sole product in high yields via the 6-exo-dig mode cyclization. The 2-alkoxy-1,3-benzothiazines were similarly produced from the o-ethynylphenyl isothiocyanates and the corresponding sodium alkoxides. (C) 2013 Elsevier Ltd. All rights reserved.