| abstract |
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. n (R 1 ) 3 P═N—Z—NH-EWG (1) |