Pure Appl. Chem., 2011, Vol. 83, No. 3, pp. 633-644
http://dx.doi.org/10.1351/PAC-CON-10-08-06
Published online 2011-01-31
Rational design of novel ligands for environmentally benign cross-coupling reactions
Abstract:
Transition-metal (TM) complexes of new phosphines, readily prepared by a straight-forward three-step modular synthesis, were successfully employed in difficult cross-coupling reactions conducted under mild conditions (water, “open-flask”, low temperature) that aspire to meet green chemistry criteria. High yielding catalyzed by bismuth or rhodium complexes oxidative arylation of naphthoquinone gave the key 2-arylnaphthoquinone intermediates for facile bismuth triflate-catalyzed Michael addition of secondary phosphine oxides. Subsequent O-methylation and reductions of the resulting products gave access to the target air-stable phosphine ligands in good overall yields (up to 60 %).
Keywords
asymmetric catalysis; C,P-complexation cross-coupling; green chemistry; phosphorus ligands.