The use of three orthogonally tagged phosphine reagents to assist chemical work-up via phase-switch scavenging in conjunction with a modular flow reactor is described. These techniques (acidic, basic and Click chemistry) are used to prepare various amides and tri-substitutedguanidines from in situ generated iminophosphoranes.
C.D. Smith, I.R. Baxendale, G.K. Tranmer, M. Baumann, S.C. Smith, R.A. Lewthwaite and S.V. Ley, Org. Biomol. Chem., 2007, 5, 1562-1568.