Formation of an unexpected rearrangement product using Grubbs' second generation catalyst: 2-allyl-3,4-dihydro-2H-1,4-benzothiazines from diene precursors
Date
2012
Authors
Morgans G.L.
Yadav D.B.
Fernandes M.A.
De Koning C.B.
Michael J.P.
Van Otterlo W.A.L.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Application of sub-stoichiometric amounts of Grubbs' second generation catalyst to the substrate N-allyl-N-[2-(allylsulfanyl)phenyl]-4- methylbenzenesulfonamide afforded the ring-closed compound 6-[(4-methylphenyl) sulfonyl]-5,6-dihydro-2H-1,6-benzothiazocine, as well as the unexpected 2-allyl-4-[(4-methylphenyl)sulfonyl]-3,4-dihydro-2H-1,4-benzothiazine. Use of similar conditions on an analogous sulfoxide resulted in the expected product, 6-[(4-methylphenyl)sulfonyl]-5,6-dihydro-2H-1,6-benzothiazocine 1-oxide, indicating that the sulfide was playing a key role in this novel transformation. Furthermore, the use of N-allyl-4-methyl-N-{2-[(2-methyl-2-propenyl)sulfanyl] phenyl}-benzenesulfonamide in the same reaction gave 2-(2-methyl-2-propenyl)-3, 4-dihydro-2H-1,4-benzothiazine. © 2012 Elsevier Ltd. All rights reserved.
Description
Keywords
Benzothiazine, Benzothiazocine, Rearrangements, Ring-closing metathesis, Ruthenium carbene
Citation
Tetrahedron Letters
53
19
2384
2387
53
19
2384
2387