Patent ID: 7223879

Claim:
A ligand represented by structure I: wherein R is selected independently for each occurrence from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, aralkyl, heteroaralkyl, and —(CH 2 ) m —R 80 ; the A and A′ rings of the biphenyl core independently may be unsubstituted or substituted with R 1 and R 2 , respectively, any number of times up to the limitations imposed by stability and the rules of valence; R 1 and R 2 , when present, are selected independently for each occurrence from the group consisting of ethyl, propyl, butyl, pentyl, hexyl, cycloalkyl, heterocycloalkyl, heteroaryl, aralkyl, heteroaralkyl, —Si(R) 3 , and —(CH 2 ) m —R 80 ; R 80 represents an unsubstituted or substituted aryl, a cycloalkyl, a cycloalkenyl, a heterocycle, or a polycycle; m is independently for each occurrence an integer in the range 0 to 8 inclusive; and the ligand, when chiral, is a mixture of enantiomers or a single enantiomer.