Chiral ligand 1a[1] is a known compound. Charaterization data of other chiral ligands (1c-h) are as follows: [2] : A light yellow solid, mp: 90-92 o C.
Ligand (S,S)-1c[α] D = +48.0 (c 1.0, CH 2 Cl 2 ). IR ν = 3416, 3058, 2964, 1471, 1449, 1377, 1268, 1217, 1004, 870, 767, 748, 703 19.5, 23.7, 24.1, 29.9, 31.7, 33.7, 55.1, 58.0, 70.1, 79.2, 123.4, 124.5, 124.7, 124.8, 125.4, 125.7, 126.0, 127.0, 127.5, 127.8, 127.9, 128.3, 128.8, 132.2, 133.2, 133.3, 140.7, 143.9, 144. 23.8, 24.3, 29.1, 32.7, 33.7, 54.1, 58.0, 71.1, 78.2, 124.7, 126.0, 126.3, 126.5, 26.8, 127.9, 128.3, 128.8, 129.2, 139.2, 139.3, 140.6, 140.7, 145.6, 146.5, 152.3 7, 23.5, 31.7, 34.0, 55.0, 57.7, 71.4,
Ligand (S,S)-1e: