Chemoselective conjugate reduction of alpha,beta-unsaturated ketones catalyzed by rhodium amido complexes in aqueous media.
Although a notable feature of Noyori's Ru-TsDPEN complex is that the transfer hydrogenation reaction is highly chemoselective for the C=O functional group and tolerant of alkenes, our early report indicated that the chemoselectivity could be switched from C=O to C=C bonds in the transfer hydrogenation of activated alpha,beta-unsaturated ketones. Now we have found that a variety of alpha,beta-unsaturated ketones, even without other electron-withdrawing functional groups, could be reduced on the alkenic double bonds with high selectivities employing amido-rhodium hydride complex in aqueous media, and up to 100% chemoselectivity has been achieved. It is notable that the chemoselectivity was improved significantly on going from organic solvent to water. Moreover, a 1,4-addition mechanism has been proposed on the basis of the corresponding experimental details and computational analysis.
Li
Xuefeng
X
National Engineering Research Center of Chiral Drugs and Key Laboratory of Asymmetric Synthesis & Chirotechnology of Sichuan Province, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China.
Li
Liangchun
L
Tang
Yuanfu
Y
Zhong
Ling
L
Cun
Linfeng
L
Zhu
Jin
J
Liao
Jian
J
Deng
Jingen
J
D000475:Alkenes / Q000737:chemistry; D002384:Catalysis; D005029:Ethylenediamines / Q000737:chemistry*; D006865:Hydrogenation; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D014867:Water / Q000737:chemistry*
D000475:Alkenes; D005029:Ethylenediamines; D007659:Ketones; D009942:Organometallic Compounds; C520782:ruthenium-(1S,2S)-N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine; D014867:Water