Journal of Organic Chemistry p. 10575 - 10584 (2015)
Update date:2022-08-03
Topics:
Sánchez-Arroyo, Antonio J.
Pardo, Zulay D.
Moreno-Jiménez, Florencio
Herrera, Antonio
Martín, Nazario
García-Fresnadillo, David
Photosensitized oxidation of trimethyl[2.2.1]bicycloheptane thioketones by 1O2 can yield more photoproducts than exclusively ketones and sulfines. Moreover, the ketone/sulfine ratio can be reversed when protic conditions and high thioketone concentrations are used, conversely to earlier results reporting ketones as the main photoproducts. A new mechanistic proposal for sulfine formation is suggested following intermolecular oxygen transfer from a peroxythiocarbonyl intermediate to a second thioketone molecule. Reaction quantum yields (10-5-10-2) depend on the reaction conditions and time. Sulfine production reaches a maximum at short irradiation times, whereas decomposition to the corresponding ketone is observed at long reaction times. When the thioketone substrate has a hydrogen atom at the α position a peroxyvinylsulfenic acid intermediate can be formed by proton transfer. Reaction of this intermediate with another thioketone molecule can yield more sulfine and its tautomeric vinylsulfenic acid, which dimerizes in situ to the thiosulfinate. The hydroperoxyl group of the peroxyvinylsulfenic acid can also rearrange to the α position, and by reaction with the starting thioketone, α-hydroxy thioketone and additional sulfine can be formed, while dehydration yields the α-oxo thioketone. In situ [2 + 2] and [4 + 2] self-cycloaddition of the α-oxo thioketone yields significant amounts of the corresponding adducts at prolonged irradiation times.
View MoreNanjing Chemipioneer Pharma&Tech Co.,Ltd
website:http://www.chemipioneer.com.cn
Contact:+86-25-52685700
Address:Room 305,A Block,Biological-Medicine Building,Business Start-up Center,Xin-ke 1st Road, High-tech development zone,Nanjing city,Jiangsu Province, China
Contact:--
Address:80G, No.1 Building, Guodu Development Mansion, No. 182 Zhaohui Road, Hangzhou City, Zhejiang Province,China.
ABA Chemicals (Shanghai) Limited
Contact:021- 5115 9199-232
Address:Suite 18D, #201 Ningxia Road,
Contact:+86-913-2223392
Address:No. 32, Xinanjing Road, Weinan City, Shaanxi Province, 714000, China
Anhui Asahikasei Chemical Co., Ltd
Contact:86-551-4259770
Address:No. 88 Linquan Road Hefei Anhui China
Doi:10.1021/om4000105
(2013)Doi:10.1016/j.bmc.2009.01.012
(2009)Doi:10.1021/om801209f
(2009)Doi:10.1007/s10593-008-0055-z
(2008)Doi:10.1016/S0040-4020(01)86883-6
(1987)Doi:10.1021/ja200941a
(2011)