Binaphthophosphepine

Binaphthophosphepines can also be synthesized from 2,2 -bis(halomethyl)-l,T-binaphthyls 96, 101, and different phosphorus-containing compounds. Thus, the BH3 adduct 17 was obtained in good yield from 2,2 -bis(bromomethyl)-1,1 -binaphthyl 96 and ammonium hypophosphite in six steps in a good yield <2003JOC3258, 20010L2525>. 

An enantioselective [3+2] cycloaddition of A-DPP-imines 226 with 2-butyno-ates 227 promoted by (5)-binaphthophosphepine (cat. 228), affording the pyrrolines 229 was reported by Marinetti, et al. Scheme 3.73 [90]. 

The same group and others have developed a flexible approach to P-stereogenic mono- and bidentate binaphthophosphepines (binepines) by one or two diastereoselective a-deprotonation steps (Scheme 2.56). 

A unique example of P-stereogenic ii(binaphthophosphepine), named BINAPINE, has been reported by Zhang and co-workers (Scheme 2.57). 

Good to excellent yields and moderate to good enantioselectivities up to 89% ee were achieved in the hydrogenation of a range of aryl, alkyl, cyclic, heterocyclic, and aliphatic ketones by H2 in the presence of Pr OH and Bu OK using a combination of Cu(OAc)2 and chiral monodentate binaphthophosphepine ligands (213) as the active and selective catalyst. ... 

In the case of a,p-unsaturated ketones, chiral binaphthophosphepine ligands L5 exhibited a clear preference towards 1,2-reduction. Thus, allylic alcohols 16 and 22 were formed in high yield and with high enantioselectivity using L5 (R=Ph). The reaction with benzylidene acetone was less selective 1,2-manifold was in competition with 1,4-manifold and a complete reduction pathways, which was also accompanied by a drop in enantiocontrol [14]. 

Junge K, Wendt B, Addis D, Zhou S, Das S, Belter M (2010) Copper-catalyzed enantio-selective hydrosilylation of ketones by using monodentate binaphthophosphepine ligands. Chem Eur J 16 68-73. doi 10.1002/chem.200902442... 

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