Synthesis of chiral functionalized phosphine ligands based on camphor skeleton

✍ Scribed by Igor V Komarov; Marian V Gorichko; Mikhail Yu Kornilov

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 642 KB
• Volume: 8
• Category: Article
• ISSN: 0957-4166
• DOI: 10.1016/s0957-4166(97)00003-7

✦ Synopsis

Reactions of some nucleophiles with (+)-8-and (+)-9-bromocamphors have been studied. It has been demonstrated that these reactions offer an attractive route for chiral compounds with the rigid camphor skeleton possessing both soft diphenylphosphanyl and hydroxyl or carbonyl groups. The compounds could be used as ligands for asymmetric catalysts realizing a secondary interaction with substrates in the substrate--catalyst complex. Different synthetic strategies have been developed for 8-and 9-substituted camphor derivatives. Reactions of (+)-8-bromocamphor with some nucleophilic reagents give compounds having a 4-oxatricyclo[~t.3.0.03,7]nonane skeleton. Analogously, reaction of 8,10-dibromocamphor with Ph2PLi can lead to a functionalized tricyclic diphosphine which is more attractive as a ligand for asymmetric catalysts than monophosphines. It is noteworthy, that the formation of the tricyclic structure prevents the known ring cleavage at the C(1)--C(2) bond of 10-bromosubstituted camphor derivatives. (~