Diastereoselective cycloadditions of 1,3-thiazolium-4-olates with chiral 1,2-diaza-1,3-butadienes
A series of 2-(N-methyl)benzylamino-1,3-thiazolium-4-olates (2-aminothioisomunchnones) react with chiral 1,2-diaza-1,3-butadienes derived from carbohydrates to afford a diastereomeric mixture of (4R,5S)- and (4R,5R)-4,5-dihydrothiophenes. These substrate-controlled cycloadditions are chemoselective, regiospecific, and proceed with a high facial diastereoselection. A theoretical rationale at semiempirical level does justify the stereochemical outcome observed in the experiments.
Avalos
M
Departamento de Quimica Organica, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain. mavalos@unex.es
Babiano
R
Cintas
P
Clemente
FR
Gordillo
R
Jimenez
JL
Palacios
JC
Raithby
PR