Phosphino sulfoximine

Scheme 1.53 Test reaction with BINOL-derived A -phosphino sulfoximines.

On the other hand, Bolm et al. have reported, more recently, the use of BINOL-derived A -phosphino sulfoximines as ligands in the rhodium-catalysed hydrogenation of dimethyl itaconate and a-acetamidoacrylates, achieving excellent enantioselectivities of up to 99% ee (Scheme 8.12). In the main... 

The synthesis of phosphino sulfoximine 97 relied significantly on the successful development of methods pursued in parallel in our group. Whereas palladium-catalyzed cross-couplings between 53 and 98 proceeded in low yield, the copper catalysis with a combination of copper(l) iodide and cesium acetate worked well, affording 99 in up to 83% yield [78]. The resulting phosphine oxides 99 were then reduced to the corresponding phosphines 97 using a mixture of trichlorosilane and triethylamine (Scheme 2.1.1.33). 

As an extension of these studies on the use of sulfoximines in asymmetric reductions, BlNOL-derived phosphino sulfoximines of the 105 type were tested in both rhodium-catalyzed hydrogenations (yielding optically active diesters 104 or amino acid derivatives Scheme 2.1.1.35) and palladium-catalyzed allylic alkylations (not shown) in collaboration with Reetz and Gais [81, 82]. Here, enantioselectivities of up to >99 and 66% ee, respectively, were achieved. 

---