Formation of N, S‐Containing Polycycles via Base Promoted Dimerization of N‐Phenacyl and N‐Benzylbenzothiazolium Bromides. Issue 3 (20th January 2020)

• Record Type: Journal Article
• Authors: Ding, Bang‐Dong; Sun, Jing; Jiang, Wang; Jin, Gong; Yan, Chao‐Guo
• Is Part Of: ChemistrySelect. Volume 5:Issue 3(2020)
• Page Start: 1092
• Page End: 1096
• Publication Date: 2020-01-20
• Subjects: benzothiazole -- benzothiazolium ylide -- benzo[d]thiazole -- N-heterocyclic carbene -- spirobi[benzo[d]thiazole].; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201904941
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: The triethylamine promoted dimerization of N‐phenacylbenzothiazolium bromides in ethanol resulted in a mixture of N, O, S‐containing six fused‐cyclic compounds and N, S‐containing five fused‐cyclic compounds in moderate yields. On the other hand, the base promoted dimerization of N‐benzylbenzothiazolium bromides selectively afforded 2, 3‐bis(4‐methylbenzyl)‐2, 3‐dihydro‐2, 2′‐bibenzo[ d ]thiazoles or 3, 3′‐bis(4‐methoxybenzyl)‐2, 2′‐spirobi[benzo[ d ]thiazoles] depending on the electronic effect of the substituents on the benzyl group. The plausible formation mechanisms of the various annulation products were rationally proposed. Abstract : Triethylamine promoted dimerization of N‐phenacylbenzothiazolium bromides in ethanol resulted in a mixture of N, O, S‐containing fused‐cyclic compounds and N, S‐containing fused‐cyclic compounds. On the other hand, the similar reaction with N‐benzylbenzothiazolium bromides selectively afforded 2, 2′‐bibenzo[d]thiazoles or 2, 2′‐spirobi[benzo[d]thiazoles].