Phosphinimines —

The use of cycloadditions for synthesizing medium-sized ring lactams is more or less restricted to the generation of seven-membered rings. The simplest method to generate azepinones seems to be the [6-1-1] reaction of a 1,6-dicar-boxylic acid chloride 148/152 and a phosphinimine 149, the in situ formed chloro enamine 150 underwent a Chapman rearrangement to give a cyclic imide 151/153 (Scheme 28)] [36]. 

The dipole moment of tributylpliosphine varies from 1.49 to 2.4 D according to the solvent used. Inductive effects in phosphines have been estimated by comparing the calculated and observed dipole moments, and the apparent dipole moment due to the lone electron pair on phosphorus has been estimated. A method of calculating the hybridization of the phosphorus atom in terms of bond angles is suggested which leads to a linear relationship between hybridization ratio and lone electron pair moment. The difference between experimental and calculated dipole moments for para-substitued arylphosphines, phosphine sulphides, and phosphinimines has been used to estimate mesomeric transfer of electrons to phosphorus. 

Staudinger, H., and Meyer, J. (1919) Uber neue organische phosphorverbindungen III. Phosphinmethyl-enderivate und phosphinimine. Helv. Chim. Acta 2, 635-646. 

Ring opening of the oxo derivative of the tetrazolo[l,5- ]pyrimidine ring system has also been reported <1996JHC229>. Treatment of the 6-hydroxyethyl-7-methyl substituted compound 59 with triphenylphosphine gave the phosphinimine derivative 60 in nearly quantitative yield (Scheme 10). 

Phosphinimines, 50, 109 Uf-Phosphinolin-4-one, 2,3-dihydro, 1-phenyl, 53, 102 Phosphonic acid, 2-(cyclo-hexylamino)vinyl-, diethyl ester, 53, 44... 

The nucleophilic addition of NaN3 leads to 2-azido-2-alkenyl phosphonates 145, which would react further with PPh3 to afford phosphinimine 147. The migration of the C=C bond in 145 was not observed. Upon photolysis, 145 can also cydize to afford azirine 146 (Scheme 10.71) [76]. 

The phosphinimines are thermally unstable and readily eliminate Me3SiBr at temperatures of greater than 100°C to form only cyclic phosphazenes (eq 3). (. 7 )... 

More importantly, the P-bromophosphinimines react smoothly with CF3CH2OH in the presence of Et3N to form P-(trifluoroethoxy)phosphinimines (eq 4) ( ). On heating in either sealed glass ampoules or a stainless... 

Phosphazene copolymers have also been prepared by the thermolysis of equimolar mixtures of the phenyl/alkyl and dialkyl substituted P-trifluoroethoxy-phosphinimines. 

Phosphinimines, 50,109 Photochemical reactions, dissociation of trihalomethanes, 52,132 rearrangement, 52, S3 Phthalic acid, reduction, 50, 50 Pivalaldehyde, by condensation of t-... 

This yellow, diamagnetic complex provides one of the few examples of metal hydrido compounds which contain only saturated ammine ligands. Osmiuin(v).—Further Os -arylimido-complexes have been synthesized via the reaction of phosphinimines with [OsOCl3(PPh3)2] ... 

Isocyanates 345 react with phenanthrenequinone 346 and triphenylarsine oxide to give photochromic oxazines 347 (Equation 48) <1993PS(81)37>. The isocyanate can be replaced by a phosphinimine and the phenanthrene structure can also be replaced by the corresponding phenanthroline (Equation 49) <2003WO42195>. The /ra r-fused tetrahydrooxazine 349 was prepared from epoxide 348 and 2-aminoethyl sulfate (ethanolamine 0-sulfonic acid) (Equation 50) <1987AP625>. 

Preparations of pyridazino[3,4- [l,3]oxazines by ozonolysis of pyrrolo[2,3-b]pyridazine-3-carboxylates and from the reaction of A -(4-ethoxycarbonylpyridazin-3-yl)phosphinimines with acyl halides were described in CHEC-II(1996) <1996CHEC-11(7)737>. A simpler form of the latter approach has now been reported <1994CC2451>, wherein the 1-A -oxide of 3-aminocinnoline-4-carboxylic acid undergoes cyclization with acetic anhydride (Equation 126). The isomeric pyridazino[4,3-, [l,3]oxazines have been prepared in a similar manner (Equation 127) <1997PHA838>. 

Reaction of phosphinimines with isothiocyanates or isocyanates to give carbodiimide [66]. 

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