THE REACTIONS OF PRIMARY PHOSPHINES INVOL VING STERICALLY DEMANDING SUBSTITUENTS - THE CASE OF 1-ADAMANTYLPHOSPHINE

The reaction of 1-AdPH2 1 with equimolar amounts of H2O2 . C(:O)(NH2)2 , Sulfur and selenium furnished the corresponding primary phosphine ox ides, sulfides and selenides, 2, 5 and 7. In these compounds the PH-pr otons may be exchanged quantitatively for deuterons by the action of C H3OD/trifluoroacetic acid anhydride, while the reaction of 1 with the same agent gave a mixture of 1-AdPH2 1, 1-AdPHD 1 a and 1-AdPD2 1b. Th e reaction of 1 with activated carbonyl compounds, R1R2C(:O) led to th e di-adducts 9 and 10 and to the mono-adduct 11 of the general type 1- AdPH2-n[C(OH)R1R2]n [n = 2 for 9 (R1 = H, R2 = CCl3) and 10 (R1 = H, R 2 = COOH); n = 1 for 11 (R1 = Ph, R2 = CF3)]. 11 decomposed in solutio n, giving 1-AdPH2 1 and trifluoroacetophenone. 1-Adamantylphospholaniu m tribromide 12 was synthesized by heating 1 in 1,4-dibromobutane and was converted into the corresponding hexafluorophosphate 12a and the o xide 13. The action of a 2.5-fold excess of phosgene on 1 gave 1-AdPCl 2 15 in high yield. The reaction of 1 -AdPH2 1 with Ph3SnCl led to the formation of P-Sn-bonds. An attempt at the separation of the mixture of the mono- and distannylation products, 16 and 17, was unsuccessful. Metal complexes of the type cis-(1-AdPH2)2MCl2 (M = Pd: 18, M = Pt: 1 9) were obtained by reaction of 1-AdPH2 1 with (COD)MCl2 (COD = 1,5-cy clo-octadiene). In the same way (NOR)Mo(CO), (NOR = norbornadiene) and (CHT)Mo(CO)3 (CHT = cycloheptatriene) reacted with two or three equiv alents of 1 to give the expected co-ordination compounds, cis-L2Mo(CO) 4 21 and fac-L3Mo(CO)3 22 (L = 1), respectively. The phosphido complex CP(CO)2Mo(mu-1-AdPH)(mu-H)Mo(CO)2Cp 23 (Cp = cyclopentadienyl) was fo rmed by refluxing a solution of 1 and [CpMo(CO)3]2 in methylcyclohexan e.