Highly modular P-OP ligands in asymmetric allylic substitution

A library of highly modular P-OP ligands have been evaluated in Pd-catalysed allylic substitutions with C- and N-nucleophiles. Catalyst optimisation via a variation of the phosphino and phosphite substituents led to a ‘lead’ catalyst, which efficiently mediated the allylic substitutions when various combinations of substrates and nucleophiles were tested. Ground-state calculations were carried out and these allowed a clearer understanding of the stereochemical outcome of the reaction.

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((1R,2S)-2-Hydroxy-3-methoxy-1-phenylpropyl)bis(4-trifluoromethylphenyl)phosphine–borane complexC24H24BF6O2PAbsolute configuration: (1R,2S)[α]D27=-116.8 (c 1.11, CHCl3)Source of chirality: asymmetric synthesis

((1R,2S)-2-Hydroxy-3-methoxy-1-phenylpropyl)bis(4-methoxyphenyl)phosphine–borane complexC24H30BO4PAbsolute configuration: (1R,2S)[α]D28=-145.9 (c 1.06, CHCl3)Source of chirality: asymmetric synthesis

((1R,2S)-1-(bis(4-(Trifluoromethyl)phenyl)phosphino)-3-methoxy-1-phenylpropan-2-yl) ((R)-1,1′-binaphthalen-2,2′-yl) phosphiteC44H32F6O4P2Absolute configuration: (1R,2S,Ra)[α]D24=-180.5 (c 0.5, CH2Cl2)Source of chirality: asymmetric synthesis

((1R,2S)-1-(bis(4-Methoxyphenyl)phosphino)-3-methoxy-1-phenylpropan-2-yl) ((R)-1,1′-binaphthalen-2,2′-yl) phosphiteC44H38O6P2Absolute configuration: (1R,2S,Ra)[α]D25=-248.4 (c 0.5, CH2Cl2)Source of chirality: asymmetric synthesis