Catalysis Communication [SOCAT]

Abstract :

Two chiral diphosphites, (S,S)-5,17-bis(1,1′-binaphthyl-2,2′-dioxyphosphanyloxy)-25,26,27,28-tetrapropyloxycalix[4]arene (1) and (S,S)-5,11-bis(1,1′-binaphthyl-2,2′-dioxyphosphanyloxy)-4(24),6(10),12(16),18(22)-tetramethylenedioxy-2,8,14,20-tetrapentylresorcin[4]arene (2), each based on a conical cavity, were synthesised and assessed in the rhodium-catalysed hydroformylation of vinyl arenes. Under optimised conditions, both ligands led to high proportions of branched aldehyde (b/l = 8.1) in the hydroformylation of styrene. The observed enantioselectivity was considerably higher for 1 than 2 (ee 89% vs. 50%), this being consistent with the easy formation of chelated intermediates with 1 (chelate formation is prevented with 2), in which the embracing ligand enables an efficient chirality transfer to the catalytic centre.

Graphical Abstract :

Macrocyclic diphosphites 1 and 2 synthesised and assessed in asymmetric hydroformylation

Reference :

Nallusamy Natarajan, Marie-Christelle Pierrevelcin, David Sémeril, Claude Bauder, Dominique Matt et Rengan Ramesh

Chiral calixarene and resorcinarene derivatives. Conical cavities substituted at their upper rim by two phosphito units and their use as ligands in Rh-catalysed hydroformylation

Catalysis Communications 118 (2019) 70–75 - DOI: https://doi.org/10.1016/j.catcom.2018.09.020

Contact chercheur :

David Sémeril, SOCAT, Institut de Chimie (UMR 7177).