Easily accessible and highly tunable bisphosphine ligands for asymmetric hydroformylation of terminal and internal
Kun Xu1, Xin Zheng, Zhiyong Wang
1Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Soft Matter Chemistry and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026 (P.R. China), Fax: (+86) 551-63603185; Department of Chemistry and Chemical Biology and Department of Medicinal Chemistry, Rutgers, The State University of New Jersey Piscataway, New Jersey 08854 (USA), Fax: (+1) 732-4456312.
Abstract:
An efficient methodology for synthesizing a small library of easily tunable and sterically bulky ligands for asymmetric hydroformylation (AHF) has been reported. Five groups of alkene substrates have been tested with excellent conversions, moderate-to-excellent regio- and enantioselectivities. Among the best result of the reported literature, application of ligand 1 c in the highly selective AHF of the challenging substrate 2,5-dihydrofuran yielded almost one isomer in up to 99 % conversion along with enantiomeric excesses (ee) of up to 92 %. Highly enantioselective AHF of dihydropyrrole substrates is achieved using the same ligand, with up to 95 % ee and up to >1:50 β-isomer/α-isomer ratio.
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