A General Catalytic Enantioselective Transfer Hydrogenation Reaction of β,β-Disubstituted Nitroalkenes Promoted by a Simple Organocatalyst.

摘要: Given its synthetic relevance, the catalytic enantioselective reduction of β,β-disubstituted nitroalkenes has received a great deal attention. Several bio-, metal-, and organo-catalytic methods have been developed, which however are usually applicable to single classes nitroalkene substrates. In this paper, we present an account our previous work on transformation, implemented with new disclosures mechanistic insights results in very general protocol for reductions. The proposed methodology is characterized by (i) remarkably broad scope encompassing various classes; (ii) Hantzsch esters as convenient (on preparative scale) hydrogen surrogates; (iii) simple commercially available thiourea catalyst; (iv) user-friendly procedures. Overall, gives practical dimension nitroalkenes, offering useful platform preparation nitroalkanes bearing stereogenic center at β-position highly enantioenriched form. A transition state model derived from control kinetic experiments combined literature data discussed. This accounts justifies observed experimental results.