Spiroketal‐Based Phosphorus Ligands for Highly Regioselective Hydroformylation of Terminal and Internal Olefins |
| |
| Authors: | Xiaofei Jia Dr Zheng Wang Prof Dr Chungu Xia Prof Dr Kuiling Ding |
| |
| Institution: | 1. State Key Laboratory of Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, 18 Tianshui Middle Road, Lanzhou 730000 (P.R. China);2. State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 (P.R. China), Fax: (+86)?21‐6416‐6128 |
| |
| Abstract: | A new class of bidentate phosphoramidite ligands, based on a spiroketal backbone, has been developed for the rhodium‐catalyzed hydroformylation reactions. A range of short‐ and long‐chain olefins, were found amenable to the protocol, affording high catalytic activity and excellent regioselectivity for the linear aldehydes. Under the optimized reaction conditions, a turnover number (TON) of up to 2.3×104 and linear to branched ratio (l/b) of up to 174.4 were obtained in the RhI‐catalyzed hydroformylation of terminal olefins. Remarkably, the catalysts were also found to be efficient in the isomerization–hydroformylation of some internal olefins, to regioselectively afford the linear aldehydes with TON values of up to 2.0×104 and l/b ratios in the range of 23.4–30.6. X‐ray crystallographic analysis revealed the cis coordination of the ligand in the precatalyst Rh( 3 d )(acac)], whereas NMR and IR studies on the catalytically active hydride complex HRh(CO)2( 3 d )] suggested an eq–eq coordination of the ligand in the species. |
| |
| Keywords: | homogeneous catalysis hydroformylation ligands olefins regioselectivity rhodium |
|
|
