Carbon dioxide with phosphoranes

Ether, a solvent with a low dielectric constant, favours cyclization over chain extension. Heating the phosphorane to 120 °C yields the alternating copolymer. Terpolymers are formed when either acrylates or acrylonitrile are copolymerized with dioxaphospholane in a carbon dioxide atmosphere. 

Further reports have appeared on the reaction of trivalent phosphorus compounds with acetylene dicarboxylates. In the first, alkyl diphenylphosphinites (e.g.57) are shown to react with dialkylacetylene dicarboxylates (e.g.58) in the presence of carbon dioxide to form 1,2-oxaphosphol-3-enes (e.g.59) which in the presence of excess phosphinite decompose via (60) to give di-ylids (e.g.61). On the other hand, the phosphoranes (62) from phosphonites and phosphites react with a further phosphorus component to give the ylids (63) which are readily converted by treatment with alcohol into phosphonates (65) apparently via ketene intermediates (64) as evidenced by and isotopic tracer studies. ... 

Carbon dioxide reacts similarly with phosphorane 1 to produce betaine 12, which is converted into the corresponding phosphonium bromide 13 upon protonation with hydrogen bromide, while alkaline hydrolysis affords cyclopropanecarboxylic acid... 

The benzimidazote-phosphorane (100.13) is readily cyctized by reaction with either carbon dioxide or carbon disulphide. 

In fully substituted R3Si-PR2-type compounds, P-Si bonds are broken by water, oxygen, carbon dioxide, carbon disulphide and some metal carbonyl complexes. Diphosphines are formed by reaction with some phosphine halides or fluoro-phosphoranes (Figure 9.10). Other Si-P bond-breaking reactions are (6.564), (6.578) and (6.600). 

Silylmethyl-Substituted Heterocumulenes. (Trimethylsilyl-methyl)iminotriphenylphosphorane is obtained from a one-pot reaction of the azide and triphenylphosphine (eq 3). The reactions of the phosphorane with carbon dioxide or carbon disulfide (eq 5) give trimethylsilylmethyl isocyanate or trimethylsilylmethyl isothiocyanate in 68 and 94% yields, respectively. ... 

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