Chiral amidophosphine ligands

Owing to strategic reasons, Lonza exited the dextrometorphan business before the process could be transferred. Subsequently a further study of the hydrogenation of 10, using iridium complexes with chiral amidophosphine-phosphonite ligands, was published by another group [14]. An enantioselectivity of 86% ee was reached, but the chemoselectivity was low. 

Lithiation of the dicarboxamide 365 is similarly diastereoselective, and after two successive n-BuLi-(—)-sparteine lithiations C2-symmetric products such as 367 can be made with high ee (Scheme 156) Attempted double lithiation of 365 in one pot fails with n-BuLi with s-BuLi-(—)-sparteine the major product is the meso isomer of 367 ". The amidophosphine 366 has been used as a chiral ligand for Pd chemistry the amides can be reduced to amino groups with BHsiTHF . 

Leautey, M. Castelot-Deliencourt, G. Jubault, P. Pannecoucke, X. Quirion, J.-C. Synthesis of a-substituted /i-amidophosphines by diastereoselective alkylation. A new access to chiral ligands for asymmetric catalysis. 

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