A Chiral Bis(arsine) Ligand: Synthesis and Applications in Palladium-Catalyzed Asymmetric Allylic Alkylations

PAULA M. UBERMAN; MINO R. CAIRA; SANDRA E. MARTÍN

ORGANOMETALLICS

AMER CHEMICAL SOC

Lugar: Washington; Año: 2013 vol. 32 p. 3220 - 3226

0276-7333

The new chiral bisarsine-ligand 1,2-bis-N-[2`-diphenylarsinobenzoyl]-1(R),2(R)-diaminecyclohexane (BiAsBA, 3) based on the backbone of the Trost modular ligand (TML) was synthesized in three steps. A useful approach to introduce the -AsPh2 group on arsine ligands by Pd-catalyzed arsination was used. The molecular structure and the configuration of BiAsBA ligand was determined by single-crystal X-ray crystallography.  In the asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate very high to complete conversion and modest enantioselectivity were achieved. Despite the low enantioselectivity obtained, the bisarsine ligand BiAsBA showed significant potential, since it provided a higher ee value than the phosphorus-containing homologous Trost Standard Ligand (TSL) with the same substrate.