Phosphorus-containing carbenes

Generation of phosphorus-containing carbenes from the corresponding diazo precursors is known. Phosphinocarbene (PC) has been also isolated as distillable oil and shown to react either as a carbene or a phosphaacetylene. ... 

Phosphorus-containing carbenes insert into the OH bond of methanol and undergo a Wolff-type rearrangement. The ease of insertion and addition depends on the group attached to the carbene carbon atom. ... 

Reaction of (l-alkynyl)carbene complexes with nitrogen- or phosphorus-containing compounds makes available a large variety of products. Among these are (enamino)carbene and ( enphosphino )carbene complexes, both of which have been widely used for the generation of organic products. 

In general, NHC have lower TEP values than phosphorus-containing ligands [19,107,115], even lower than 2056 cm", the TEP value of the most basic trialkyl phos-phane PBu j [115]. The accepted interpretation is that these carbene ligands are very strong... 

Khaskin, B.A., Molodova, O.D., and Torgasheva, N.A., Reactions of phosphorus-containing compounds with diazo-compounds and carbenes, Usp. Khim., 61, 564, 1992 Russ. Chem. Rev., 61, 306, 1992. 

Several products are possible on photolysis of phosphaalkenes, which proceeds with inversion of polarity of the phosphorus-carbon bond and cleavage into transient phosphinidine and carbene species. The reactions of phosphaalkenes of the type (172) with molecular oxygen (or elemental sulphur) in refluxing benzene are sluggish, leading eventually to a phosphorus-containing... 

The reaction of a nitrogen-substituted silylene (88) with a 2H-azaphosphirene (87) gave a bicyclic compound (89), which contains an Si-Si bond and a tungsten-bound carbene.96 Compound (89) was isolated in 62% yield and its crystal structure was described. However, when an extra phosphorus atom was inserted into the ring as in (90), the monocyclic (91) was isolated in 90% yield. A crystal structure for (91) was also reported. 

A series of four-membered Si- or P-containing heterocycles was produced in various yields by electrocyclization or [2-t-2]-dimerization of compounds with multiple carbon-silicon or carbon-phosphorus bonds. These unsaturated species are formed under photolysis of diazo compounds containing a P or Si atom in an a position with respect to the diazo group, following a [l,2]-sigmatropic shift in the intermediate carbene. 

The year s reviews cover phosphorylated indoles, phosphorus-selenium compounds, phosphoryl carbenes, phosphorus-sulphur compounds, and steroid phosphates, as well as the synthesis of phosphorus esters via oxyphosphoranes. A review on phosphonates contains many interesting applications of some of the well-tried syntheses of these as analogues of natural phosphates. ... 

Sc-P bonds of a four-coordinate scandium phosphinidene complex has been determined (13JA14784). Reactions of electrophilic carbenes with white phosphorus in benzene afforded Pg clusters supported by four carbenes or a carbene—P4 adduct (13CC4486). A mechanistic insight into CO capture by amidophosphoranes which contain a highly reactive P—N bond within a four-membered ring, has been published (13CAJ3147). 

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