Rh Phebox

The catalytic system of Rh(Phebox) and MePl SiH was applied to the coupling of acetone and cinnamates under solvent-free conditions (Scheme 16) [30]. Several cinnamates and crotonates were used as enolate... 

Scheme 16 Rh(Phebox) catalytic system toward ketones...

Fig. 5 Crystal structures of active site of artificial metalloproteins a Cu(Sal-Phe) apo-Mb, and b Rh Phebox apo-A71G Mb taken from PDB ID 2EB8, and 2EF2, respectively...

Taylor et alP applied an asymmehic variant of this reaction using a Rh-BINAP catalyst and aldehydes, e.g., 296, as aeceptors to yield aldol produets sueh as 298. Although a variety of aromatie, eyelie, and acyelic aldehydes was effective acceptors, the scope of the o,P-unsaturated ester was limited to phenyl acrylate 297, and the enantioseleetivity and syn/anti seleetivities still need to be improved. Shiomi et reported an asymmetrie reduetive eoupling reaction of enones and aromatic aldehydes using ehiral Rh(Phebox) catalysts. Diphenylmethylsilane was used as a hydride donor in this ease, and the desired P-hydroxyketones were produced with up to 93% ee. 

Racemic Rh-BINAP catalyst has been employed in the arylation of enones with ArInCl2, which proceeds in THF-MeOH at 110 Conjugate hydrosilylation of diarylacrylates Ar Ar C=CHC02R with (EtO)2MeSiH, catalysed by the Rh-Phebox complex (515), has been reported to proceed with <99%... 

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