Prior ligand exchange, followed by ligand coupling in the reaction of 2-pyridyl 2-thienyl sulfoxide with 2-thienyllithium or 2-selenophenyllithium

✍ Scribed by Shigeru Oae; Yoichi Inubushi; Masakuni Yoshihara

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 468 KB
• Volume: 5
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/hc.520050306

✦ Synopsis

2-Pyridyl2-thienyl sulfoxide was found to react with variously substituted 2-thienyllithiums and 2-selenophenyllithium, exclusively affording 2-(2-pyri-dy1)thiophenes and 2-(2-pyridyl)-selenophene and the disulfides h v e d from the substituted thiophenes and selenophene. Apparently, ligand exchange precedes ligand coupling. The coupling product always involved the pyridine nucleus, but no bithienyl-type products were formed.

INTRODUCTIOiV

Since the introduction of the concept of the ligand coupling within sulfurane intermediates [ 1-31, numerous studies have been carried out, mainly by us. From an early period, there were numerous questions regarding the abilities of many different ligands for coupling and exchange. We have known for years [2-141 that heteroaromatic ligands, such as pyridyl, thien:yl and furanyl, undergo both li-Dedicated to Prof. Adrian Gibbs Brook on the occasion of his *To whom correspondence should be addressed. seventieth birthday.