SYNTHESIS AND REACTIONS OF SOME LITHIUM P HOSPHINOFORMATES R(2)PCOOLIAND RHPCOOLI - AB-INITIO CALCULATIONS IN THE H2PCOOH-PH3 CO2 SYSTEM/

The preparation of lithiumphosphinoformates R(2)PCOOLi 1 (R = Ph, c-He xyl, i-Pr, Et) and RHPCOOLi 2 (R = Ph, c-Hexyl) from R(2)PLi or RPHLi and CO2 is described. In the latter reaction RP(COOLi)(2) 3 and RPH(2) are formed in addition to 2. In protic media 1-3 are rapidly decompos ed with decarboxylation and formation of R(2)PH and RPH(2), respective ly. Reactions of 1 with Mel, (MeO)(2)SO2, Me(3)SiCl and CS2 are simila r to those of Ph(2)PCOONa and no significant influence of R was detect ed. With (MeO)(2)SO2 mixtures of 2 and 3 gave esters RHPCOOMe and RP(C OOMe)(2) while with Me(3)SiCl RHPCOOSiMe(3) was obtained as the sole p roduct. Ab initio MO calculations (GAUSSIAN 90 system of programs; HF/ 3-21G, HF/6-31G** and MP2/6-31G** basis sets) showed the phosphinofor mic acid to be less stable than its decomposition products, from which it is separated by a high barrier of isomerization. Therefore the aci d should be stable in the rarefied gas phase.