Diphenylthiophosphoramide ligand

An extension of the asymmetric condensation of organometallics onto aldehydes is the enantioselective silver-promoted allylation reaction of aldehydes with allyltributyltin, which has recently been performed by Shi et al. in the presence of chiral diphenylthiophosphoramide ligands and more efficiently, with binaphthylthiophosphoramide ligands. According to the nature of the ligand substituents, the corresponding allylation products were obtained in enantioselectivities of up to 98% ee, as depicted in Scheme 3.70. 

In 2007, a novel C2-symmetric diphenylthiophosphoramide ligand was found to be a fairly efficient chiral ligand for the Cu(I)-promoted 1,3-dipolar cycloaddition of imines and pyrrole-2,5-dione derivatives to give the corresponding adducts in moderate to good enantioselectivities and good yields (Scheme 10.14). ... 

Scheme 10.14 1,3-Dipolar cycloadditions of azomethine ylides with C2-symmetric diphenylthiophosphoramide ligand.

Shi and Wang reported that the catalyst generated from AgOTf and a chiral diphenylthiophosphoramide ligand, which was prepared from chiral 1,1 -binaphthyl-2, 2 -diamine, could promote the allylation reaction of allyltributyltin and aromatic aldehydes (Table 9.4).8 Thus, the reaction of allyltributyltin and aldehyde in the presence of AgOTf and chiral diphenylthiophosphoramide gave the corresponding adducts with up to 98% ee. 

In 1999, Shi el al. showed that a diphenylthiophosphoramide derived from (li ,2i )-l,2-diaminocyclohexane could be used as a ligand in the catalytic asymmetric addition of ZnEt2 to aldehydes in the presence of Ti(Oi-Pr)4, providing the corresponding alcohols in enantioselectivities of 40-50% ee (Scheme 3.20). Another class of new ligands such as the phenylthio-phosphoramide of (7 )-1,1 -binaphthyl-2,2 -diamine was developed by the same group, and further tested as a ligand in the same conditions (Scheme 3.20). ... 

A variety of C2-symmetric diphenyl-phosphoramides, -thiophosphoramides and -selenophosphoramides have been used as chiral catalysts in alkylation reactions. ° " ° Compounds (350) and (351) ° and the selenophosphoramidates (352), (353), and (354) " act as ligands in Ti(IV)-catalysed asymmetric addition reactions of diethylzinc to aldehydes to give secondary alcohols with e.e. values of 40 to 83%. The diphenylthiophosphoramidates(351), (355), and (356) similarly act as ligands in Ag(I)-promoted enatioselective allylation of aldehydes with... 

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