Carbon-phosphorus bonds

Three-bond carbon-phosphorus couplings JCP depend on configuration, as expected, transoid couplings being larger than cisoid ones, as demonstrated for cyclohexyl- and 2-norbornylphosphonates in Table 4.52. The Karplus relation (4.13) can be derived from the data for 2-norbornyl derivatives [376]. 

Carbon-phosphorus bonds are formed by the allylation of various phosphorus compounds. The allyldiphenylphosphine sulfide 346 is formed by the reaction of allylic acetates with lithium diphenylthiophosphide 343[215]. 

Dialkylphosphinous acids react with perfiuoroalkenes under free radical conditions to form carbon-phosphorus bonds [10] (equation 7)... 

The initial step of olefin formation is a nucleophilic addition of the negatively polarized ylide carbon center (see the resonance structure 1 above) to the carbonyl carbon center of an aldehyde or ketone. A betain 8 is thus formed, which can cyclize to give the oxaphosphetane 9 as an intermediate. The latter decomposes to yield a trisubstituted phosphine oxide 4—e.g. triphenylphosphine oxide (with R = Ph) and an alkene 3. The driving force for that reaction is the formation of the strong double bond between phosphorus and oxygen ... 

The Arbusov reaction is one of the best known methods for creating a carbon-phosphorus bond. In its simplest form (Michaelis-Arbusov) an alkyl halide reacts with a trialkyl phosphite to an alkanephosphonic acid diester as shown in Eq. (29) ... 

Engel, R. Synthesis of Carbon-Phosphorus Bonds, CRC Press Boca Raton, FL 1988, and references cited therein. 

A brief history of (3p-2p)7i bonds between phosphorus and carbon followed by an introduction to the methods of phosphaalkene synthesis that are pertinent to this review will be provided. The earliest stable compound exhibiting (3p-2p)7x bonding between phosphorus and carbon was the phosphamethine cyanine cation (1) [33]. An isolable substituted phosphabenzene (2) appeared just two years later [34]. The parent phosphabenzene (3) was later reported in 1971 [35]. These were remarkable achievements and, collectively, they played an important role in the downfall of the long held double bond rule . The electronic delocalization of the phosphorus-carbon multiple bond in 1-3, which gives rise to their stability, unfortunately prevented a thorough study of the chemistry and reactivity of the P=C bond. 

The field of carbon-phosphorus double or triple bonds has been covered in several recent reviews [1-4a]. 

Carbon-phosphorus double bonds are also formed in addition reactions of tris(trimethylsilyl)phosphine 1692 (which can be readily prepared from white phosphorus, sodium, and TCS 14 [13a,b,c]) to give oxazohum fluorides 1691 which then give the azaphospholes 1694, via 1693 [3, 14]. On addition of 1692 to 1695, the diazaphosphole 1696 [3, 15] is prepared, whereas l,3-azaphospholo[l,2a]pyridines 1698 [16] are formed from 1692 and 1697, and 1,3-thiaphospholes 1700 are formed from the dithiohum fluorides 1699 [17]. l,3-Benzodiphospholyl anions 1703 are generated by reaction of acid chlorides with the dihthium salts 1701, via 1702 [18] (Scheme 11.3). 

The phosphonium salt (116) gave the phosphorane (117) with phenyl-lithium although it has hydrogen atoms attached to carbon bonded to phosphorus. ... 

Cook AM, CG Daughton, M Alexander (1979) Benzene from bacterial cleavage of the carbon-phosphorus bond of phenylphosphonates. Biochem J 184 453-455. 

Chen C-M, Q-Z Zhuang, Z Zhu, BL Wanner, CT Walsh (1990) Molecuar biology of carbon-phosphorus bond cleavage Cloning and sequencing of the phn (psiD) genes involved in alkylphosphonate uptake and C-P lyase activity in Escherichia coli. J Biol Chem 265 4461-4471. 

La Nauze JM, H Rosenberg, DC Shaw (1970) The enzymatic cleavage of the carbon-phosphorus bond purification and properties of phosphonatase. Biochim Biophys Acta 212 332-350. 

Wanner BL (1994) Molecular genetics of carbon-phosphorus bond cleavage in bacteria. Biodegradation 5 175-184. 

The decomposition of nitrilotrimethylenetriphosphonic acid in acid solution has been studied. At 125-175° and pH 1.5, carbon-phosphorus bond cleavage occurs, but in 5M HC1 aq. carbon-nitrogen fission becomes important.1" ... 

The rule in carbon-13 NMR is that sp2-hybridized carbons (carbonyl, aromatic, olefinic) absorb at lowest field, followed by sp-hybridized (acetylenic, nitrile) and sp3 (aliphatic). A first glance leads us to believe we have seven signals, but we must remember that the methine carbon is directly bonded to phosphorus, so that we shall expect a relatively large C-P coupling. The other C-P couplings will probably be very much smaller. 

A very special class of phosphorus based ligands are ambidentate, anionic phosphinomethanides I, since, due to the same number of valence electrons and bonds, both phosphorus and carbon are comparable in their reactivity and may compete for electrophiles. 

Engel R (1988) Synthesis of carbon-phosphorus bonds. CRC, Boca Raton, FL... 

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