Microwave-assisted manganese(III) acetate based oxidative cyclizations of alkenes with β-ketosulfones
摘要:
The microwave-assisted synthesis of 5-(4-nitrophenyl)-2-phenyl-4-(phenylsulfonyl)-2,3-dihydrofuran (5a) was performed via manganese(Ill) acetate based oxidative cyclization of 1-(4-nitrophenyl)-2(phenylsulfonyl)ethanone (3a) with vinylbenzene (4a). This new protocol was applied to four sulfone derivatives (3a-d), using vinylbenzene (4a) and diphenylethene (4b), affording a series of 2,3-dihydrofurans (5a-d, 6a-d) in moderate to good yields (26-55%). Similar methodology, applied on allylbenzene (4c), surprisingly, led to dehydronaphthalene derivatives (7a-d) in moderate yields. The unexpected mechanism and the role of allylbenzene (4c) are herein discussed. (C) 2008 Elsevier Ltd. All rights reserved.
Microwave-assisted manganese(III) acetate based oxidative cyclizations of alkenes with β-ketosulfones
作者:Christophe Curti、Maxime D. Crozet、Patrice Vanelle
DOI:10.1016/j.tet.2008.10.080
日期:2009.1
The microwave-assisted synthesis of 5-(4-nitrophenyl)-2-phenyl-4-(phenylsulfonyl)-2,3-dihydrofuran (5a) was performed via manganese(Ill) acetate based oxidative cyclization of 1-(4-nitrophenyl)-2(phenylsulfonyl)ethanone (3a) with vinylbenzene (4a). This new protocol was applied to four sulfone derivatives (3a-d), using vinylbenzene (4a) and diphenylethene (4b), affording a series of 2,3-dihydrofurans (5a-d, 6a-d) in moderate to good yields (26-55%). Similar methodology, applied on allylbenzene (4c), surprisingly, led to dehydronaphthalene derivatives (7a-d) in moderate yields. The unexpected mechanism and the role of allylbenzene (4c) are herein discussed. (C) 2008 Elsevier Ltd. All rights reserved.