Methylphosphine

Organophosphorus compounds. Phosphorus-carbon bond fonnation takes place by the reaction of various phosphorus compounds containing a P—H bond with halides or tritlates. Alkylaryl- or alkenylalkylphosphinates are prepared from alkylphosphinate[638]. The optically active isopropyl alkenyl-methylphosphinate 778 is prepared from isopropyl methylphosphinate with retention[639]. The monoaryl and symmetrical and asymmetric diarylphosphi-nates 780, 781, and 782 are prepared by the reaction of the unstable methyl phosphinate 779 with different amounts of aryl iodides. Tnmethyl orthoformate is added to stabilize the methyl phosphinate[640]. 

A number of phosphorus containing polyimides were synthesized by Varma and coworkers and their properties were studied [137-141]. Polyimides have also been synthesized by the reaction of benzophenonetetra-carboxylic dianhydride (BTDA) and bis(3-aminophen-yl)methylphosphine oxide [142]. Copolyimides were... 

Extractants derived from the carbamoylmethylphosphoryl moiety (CMP) were studied in the phosphonate, phosphinate, and phosphine oxide classes. Our studies focused on dihexyl-N,N-diethylcarba-moylmethylphosphonate, DHDECMP, hexyl hexyl-N,N-diethylcarbamoyl-methylphosphinate, HHDECMP, and octyl(phenyl)-N,N-diisobutylcarba-moylmethylphosphine oxide, 0D[ IB]CMP0. The three types of CMP extractants were compared on the basis of nitric acid and extractant dependencies for Am(III), solubility of complexes on loading with Nd(III) and U(VI), and selectivity over fission products. On the basis of the above data two conceptual flowsheets were developed. The first flowsheet involves the extraction of all of the actinides from HLLW using 0.4 M 0D[IB]CMP0 in DEB. The second flowsheet involves the extraction of all of the actinides from dissolved spent LWR fuel using 0.8 M DHDECMP in DEB. 

Hexavalent Pu—See Valence states Hexyl hexyl- V, V-diethylcarbamoyl-methylphosphinate, actinide... 

Alkyldimethylphosphine-boranes 74 underwent enantioselective deprotonation employing (-)-sparteine/s-BuLi, followed by oxidation with molecular oxygen [91, 92] in the presence of triethyl phosphite (Scheme 12) to afford moderate yields of enantiomerically enriched alkyl(hydroxymethyl)methylphosphine-bo-ranes 76, with 91-93% ee in the case of a bulky alkyl group and 75-81% ee in the case of cyclohexyl or phenyl groups [93]. Except for the adamantyl derivative (in which the ee increased to 99%), no major improvement in the ee was observed after recrystallization. 

Isopropyl (/ )-( —)-methylphosphinate (134) has been prepared" in > 90% optical purity by Raney nickel desulphurization of optically pure O-isopropyl (5)-(-f-)-methyIphosphonothioate (135). The phosphonate (134) is rapidly racemized by base, but not by acid, unlike secondary phosphine oxides"" [although whether these have been prepared optically active now seems doubtful (see Chapter 4)]. The phosphinate (134) can be reconverted into 89% optically pure (5)-( + )-(135) by addition of sulphur in dioxan. As shown in the Scheme, a series of interconversions has been used to establish the configurations. 

Cycloamylose forms inclusion complexes stereoselectively with the enantiomers of isopropyl methylphosphinate (124) from which it was possible to isolate one enantiomer with an optical purity of 66%. The absolute configuration of menthyl methylphosphinate has been revised to the opposite of that previously assigned. 

More than 35 years ago, it was reported that the reaction of tri-methylphosphine with the cyclotetraphosphine (CF3P)4 affords the phosphine-phosphinidene complex, Me3P —> PCF3 (43). More recently, it has been demonstrated that stable carbenes are sufficiently nucleophilic to effect the depolymerization of cyclopolyphosphines and cyclopolyarsines to produce carbene-pnictinidene complexes 66-70, the first examples of p-block pnictinidenes (44, 45). Two extreme canonical forms, 71 and 72, can be written for such species. Structure 71... 

Benschop, H.P. and Van den Berg, G.B., Stereospecific inclusion in cycloamyl-oses partial resolution of isopropyl methylphosphinate and related compounds, Chem. Commun., 1431, 1970. 

Vedejs, E. and Donde, Y., Stereogenic P-trisubstituted phosphorus by crystallization-induced asymmetric transformation A practical synthesis of phe-nyl(o-anisyl)methylphosphine borane, /. Am. Chem. Soc., 119, 9293, 1997. 

The reaction of O-ethyl methylphosphinate (1567) and diethyl aceta-midomethylenemalonate (1568) in the presence of sodium ethoxide gave an addition product (1569), which was then hydrolyzed with concentrated hydrochloric acid [74RC1119 83PS( 17)21],... 

Spin-Spin Coupling.—The relative roles of different coupling mechanisms in organophosphorus compounds have been studied theoretically.66 The spin-spin interaction constants for methylphosphine have been calculated by the MO-LCAO method.67 Unresolved isotropic coupling to boron caused broadening of the vinyl... 

The dipole moment of phosphabenzene is reinforced by the methyl group shown in (147) and increases it from 1.46 to 1.77 D thus it resembles pyridine, which has the heteroatom at the negative end of the dipole.181 The magnitudes and trends of the dipole moments of the methylphosphines have been investigated by MO studies and the dipoles partitioned into bond moments, bond polarization, and lone-pair moments.182 The reciprocal effects of the double bond and the phosphorus atom in... 

Methylphenol, see Phenol Methyl phenyl sulfone, see Fonofos Methyl phosphate, Trichlorfon IV-Methylphosphinic acid, see Glvphosate 2-Methylpropanal, see 2-Methylpropene, 2,2,4-... 

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