A reductive cross coupling reaction process for functionalization of a nucleophilic alkene can be achieved. The nucleophilic alkene and a nucleophilic cross coupling partner compound can be reacted in the presence of an oxidizable alcohol and a suitable catalyst to form a reductive coupling product. Various additives can also be useful to refine the process such as by mitigating certain undesirable intermediates, facilitating specific site selectivity for various substitutions or reaction sites, etc. Chiral additives can be optionally used which act to provide asymmetric catalysis, e.g. allow for regioselective and stereoselective production of reductive coupling products. A reductive cross coupling pathway can include oxidizing the oxidizable alcohol to form a catalyst hydride. The nucleophilic alkene can be inserted into the catalyst hydride to form a catalyst-alkyl intermediate. Further, the catalyst-alkyl intermediate can be transmetallized with the nucleophilic cross coupling partner compound to form a transmetallated intermediate. The catalyst can be reductively eliminated to form the reductive coupling product and a reduced catalyst. Finally, the reduced catalyst can be oxidized under aerobic conditions, for example with oxygen, to form the oxidized catalyst and subsequent repetition through the cyclic pathway.
The rational design of bis(oxazoline)-copper(II) catalysts based on postulated intramolecular secondary n-cation interaction for the highly enantioselective Diels-Alder reaction is presented. A theoretical calculation suggested that the n electrons of the 4,4'-sulfonamidomethyl groups successfully interact with the Cu(II) cation and that the counteranions with protons of sulfonamido groups. These secondary interactions might be essential for the high catalytic activity, the broad range of substrates, and the high level of induction of the enantioselectivity.
US8088346B2
申请人:——
公开号:US8088346B2
公开(公告)日:2012-01-03
The first 4,4′-imidazolium-tagged C<sub>2</sub>-symmetric bis(oxazolines): application in the asymmetric Henry reaction
Highly efficient and recyclable imidazolium-tagged bis(oxazolines), with an imidazolium tagged onto the 4,4′-position of the box, have been designed and prepared for the first time. They have been synthesized from dimethylmalonic acid and used as chiral ligands in the copper(II)-catalyzed classic asymmetric Henry reaction between aldehydes and nitromethane. A systematic analysis of the anions showed