Patent ID: 8410247

Claim:
A method for forming an amide bond in an aqueous solution which comprises forming a phosphinothioester from a corresponding water soluble phosphinothiol, and thereafter reacting the phosphinothioester with an azide in an aqueous solution to form the amide bond, wherein the water soluble phosphinothiol has formula: or protonated ions, quaternary ammonium ions or salts thereof wherein: n and m are 0, 1, or 2 and n+m is 1 or more; R 1 and R 2 are linkers that are organic biradicals which are selected from optionally substituted arylenes, optionally substituted heteroarylenes, optionally substituted alkylenes, or optionally substituted cycloalkylenes or combinations thereof; n and m are 0, 1, or 2 and n+m is 1 or more; and each R 3 -R 6 , independently, is selected from guanidine, alkyl, alkenyl, alkynyl, aryl, or heteroaryl all of which are optionally substituted and wherein R 3 and R 4 or R 5 and R 6 or both combinations of groups are optionally linked to form a 5-8 member ring which contains N and optionally contains one or more additional heteroatoms; wherein substitution, when present, is substitution with one or more groups selected from halogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocycyl, —OH, —OR, —COH, —COR, —COOH, —COOR, or —N(R) 2 , where each R is independently selected from optionally substituted alkyl, alkenyl, alkynyl, heterocyclic, aryl or heteroaryl groups.