Allylic Oxidations Catalyzed by Dirhodium Catalysts under Aqueous Conditions
申请人:Doyle Michael P.
公开号:US20090093638A1
公开(公告)日:2009-04-09
The present invention relates to compositions and methods for achieving the efficient allylic oxidation of organic molecules, especially olefins and steroids, under aqueous conditions. The invention concerns the use of dirhodium (II,II) “paddlewheel complexes, and in particular, dirhodium carboximate and tert-butyl hydroperoxide as catalysts for the reaction. The use of aqueous conditions is particularly advantageous in the allylic oxidation of 7-keto steroids, which could not be effectively oxidized using anhydrous methods, and in extending allylic oxidation to enamides and enol ethers.
Efficient aziridination of olefins catalyzed by dirhodium catalysts
申请人:Doyle P. Michael
公开号:US20060211870A1
公开(公告)日:2006-09-21
This invention relates to compositions and methods for achieving the efficient aziridination of organic molecules, especially olefins. More specifically, the invention is directed to a mild, selective, and efficient aziridination protocol that involves catalysis by a mixed-valent dirhodium(II,III) catalyst (Rh
2
5+
). Especially preferred sources for forming such mixed-valent dirhodium(II,III) catalyst (Rh
2
5+
) are dirhodium(II) carboxamidates, such as dirhodium(II) caprolactamate, and their derivatives and analogues.
Hypervalent iodine-mediated aminobromination of olefins in water
作者:Xue-Liang Wu、Guan-Wu Wang
DOI:10.1016/j.tet.2009.08.069
日期:2009.10
The PhI(OAc)2-catalyzed aminobromination of electron-deficient olefins has been achieved in pure water with TsNH2 and NBS as nitrogen and bromine sources, respectively. With a catalytic amount of PhI(OAc)2, various olefins including α,β-unsaturated ketones, cinnamates, and cinnamides could be aminobrominated efficiently, giving the vicinal bromoamines in good yields and high regio- and diastereoselectivities
Bromosulfonamidation of Alkenes using S,S-Dimethyl-N-(p-toluenesulfonyl)sulfilimine
作者:Sadagopan Raghavan、S. Ramakrishna Reddy、K. A. Tony、Ch. Naveen Kumar、S. Nanda
DOI:10.1055/s-2001-14910
日期:——
A new method for the bromosulfonamidation of olefins using a combination of S,S-dimethyl-N-(p-toluenesulfonyl)sulfilimine and N-bromosuccinimide is disclosed herein.
Efficient Aziridination of Olefins Catalyzed by Mixed-Valent Dirhodium(II,III) Caprolactamate
作者:Arthur J. Catino、Jason M. Nichols、Raymond E. Forslund、Michael P. Doyle
DOI:10.1021/ol0510973
日期:2005.6.1
A mild, efficient, and selective aziridination of olefins catalyzed by dirhodium(II) caprolactamate [Rh-2(cap)(4)center dot 2CH(3)CN] is described. Use of p-toluenesulfonamide (TsNH2), N-bromosuccinimide (NBS), and potassium carbonate readily affords aziridines in isolated yields of up to 95% under extremely mild conditions with as little as 0.01 mol% Rh-2(cap)(4). Aziridine formation occurs through Rh-2(5+)-catalyzed aminobromination and subsequent base-induced ring closure. An X-ray crystal structure of a Rh-2(5+) halide complex, formed from the reaction between Rh-2(cap)(4) and N-chlorosuccinimide, has been obtained.