The present invention provides a bifunctional catalyst of the formula (1): wherein: each R
1
is independently selected from an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, an optionally substituted aralkyl group and an optionally substituted alkaryl group; Z represents a divalent organic linking moiety optionally containing one or more stereocentres; and EWG represents an electron-withdrawing group.
(R
1
)
3
P═N—Z—NH-EWG (1)
Bifunctional Iminophosphorane Organocatalysts for Enantioselective Synthesis: Application to the Ketimine Nitro-Mannich Reaction
作者:Marta G. Núñez、Alistair J. M. Farley、Darren J. Dixon
DOI:10.1021/ja409121s
日期:2013.11.6
readily synthesized via a last step Staudinger reaction of a chiral organoazide and a triarylphosphine. Their application to the first general enantioselective organocatalytic nitro-Mannichreaction of nitromethane to unactivated ketone-derived imines allows the enantioselective construction of β-nitroamines possessing a fully substituted carbon atom. The reaction is amenable to multigram scale-up, and the
Creation through Immobilization: A New Family of High Performance Heterogeneous Bifunctional Iminophosphorane (BIMP) Superbase Organocatalysts
作者:Anna M. Goldys、Marta G. Núñez、Darren J. Dixon
DOI:10.1021/ol5029942
日期:2014.12.19
An immobilized chiral bifunctional iminophosphorane superbase organocatalyst has been developed and applied in a range of challenging enantioselective reactions. A unique feature of this novel catalytic system is that the final step creation of the iminophosphorane occurs at the point of immobilization. The utility of the immobilized catalyst system was demonstrated in the nitro-Mannich reaction of ketimines as well as the conjugate addition of high pK(a) 1,3-dicarbonyl pro-nucleophiles to nitrostyrene. Catalyst recycling was also demonstrated.