Water soluble phosphanes, XIV. Hydrophilic derivatives of triphenylphosphane with NH2, COOH and P(O)(OR)(2) functionalized side chains

Nucleophilic phosphanylation of ortho-fluorophenylacetic acid or ortho-fluo robenzylamine with PhPH2 using KOtBu as the base affords the hydrophilic te rtiary phosphanes 3 and 4a with terminal CH2-COOH and CH2-NH2 substituents. The corresponding secondary phosphane ligands 2 or i may be obtained by Pd -catalyzed P-C coupling of ortho-iodophenylacetic acid with PhPH2 or select ive nucleophilic phosphanylation of ortho-fluorophenylacetic acid. Novel ph osphonatomethyl derivatives 7a, 7b of triphenylphosphane have been obtained in a two stage synthesis using ortho-iodobenzylchloride or meta-iodobenzyl bromide as starting materials. Arbusov reaction with P(OEt)3 and Pd-catalyz ed P-C coupling reactions with Ph2PH gave the esters 7a, 7b. Purification o f 7a was achieved via its BH3 adduct 8a. Deprotection, hydrolysis and neutr alisation with NaOH affords the water soluble sodium salts 9a,9b. alpha-Hyd roxy and alpha-benzylamino derivatives 12 and 14 of ortho-diphenylphosphano benzyl phosphonate (e.g. 7a) and the corresponding Me2P(O) analogs 13 and 1 6 are accessible in a straightforward manner by addition of (MeO)(2)P(O)H o r Me2P(O)H to ortho-phosphanobenzaldehyde IIa or its benzaldimino derivativ e 15, respectively. An improved synthesis for 11a-11c has been developed. R eaction of 11a with the Wittig reagent Ph3P=C(PI)COOEt and subsequent hydro lysis of the intermediate ester 17a affords ortho-diphenylphosphano cinnami c acid 17. The catalytical activity of 1, 9a, 9b and related ligands in Suz uki-type couplings reactions has been investigated.