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Substrate‐Selective Olefin Hydrogenation with a Cavitand‐Based Bis( N ‐anisyl iminophosphorane)
Author(s) -
Chavagnan Thierry,
Bauder Claude,
Sémeril David,
Matt Dominique,
Toupet Loïc
Publication year - 2017
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201601125
Subject(s) - cavitand , chemistry , steric effects , olefin fiber , regioselectivity , moiety , catalysis , selectivity , medicinal chemistry , ligand (biochemistry) , rhodium , chelation , substrate (aquarium) , stereochemistry , organic chemistry , crystal structure , supramolecular chemistry , biochemistry , receptor , oceanography , geology
A distally‐substituted resorcin[4]arene cavitand equipped with two remote N ‐anisyl‐imino‐phosphoranyl (AIP) units has been synthesised and assessed in the competitive hydrogenation of α‐olefins (rhodium catalyst). A substrate‐selectivity factor of 39.2 in favour of the linear olefin was observed after 1 h in the reduction of stoichiometric amounts of hex‐1‐ene and 3‐ethyl‐pent‐1‐ene. The catalyst was also shown to be suitable for the regioselective reduction of a compound that has two double bonds in different steric environments. The remarkable olefin discrimination probably arises from the ability of the ligand to generate a cavity‐capping N , O ‐chelator involving both AIP groups. Chelate formation positions the reactive metal sites inside the receptor moiety, the restricted size of which may retard the coordination of larger α‐olefins. The results of this study encourage the further development of cavitands as shape‐selective catalysts.