Phosphorus heterocyclic compounds

Phosphorus heterocyclic compounds, 1, 493-538 five-membered ring systems, 1, 513-523 nomenclature, 1, 496 six-membered ring systems, 1, 497-513 Photoaromatization oxirenes from, 7, 125-126 Photobleaching chromenes in, 3, 880 Photochemical reactions heterocyclic compound synthesis from, 5, 159 reviews, 1, 56 heterocyclic compounds reviews, 1, 71, 72... 

Beugelmans, R. and Chbani, M. (1995) SRN1 — synthesis of nitrogen, sulfur and phosphorus heterocyclic compounds... 

In 1987, a new class of phosphorus heterocyclic compounds was developed by Cowley and coworkers, incorporating keto groups within various phosphorus-containing rings [37]. At the time, only the synthesis of these compounds was reported via reaction between a silylated phosphane and an acyl chloride (Scheme 12.7). More recently, we developed the diketophosphepin as a multifunctional material involving the seven-membered phosphorus ring (28a-d Figure 12.19)... 

Three-membered heterocyclic compounds are available when one atom fragments like carbenes [108 or phosphorus compounds [109] add to C=0 ot C=N bonds (equation 26)... 

The first chapter covers organometallic complexes of boron, silicon, and phosphorus analogs of azoles. This chapter continues the series by A. P. Sadimenko (Fort Hare, South Africa) in which he is treating comprehensively organometallic complexes of heterocyclic compounds. So far, he has covered, in the volumes of AHC indicated, complexes of the following heterocycles ... 

Zwitterionic heterocyclic compounds with two phosphorus atoms of opposite charge and different coordination were a rarity 10 years ago. This field has emerged recently with the reports of a variety of new structures as shown in Schemes 12,13,and 14. Schevchenko and Schmutzler described a compound of... 

The third chapter Recent Developments in the Chemistry of N-Heterocyclic Phosphines presents a survey on five- and six-membered phosphorus-nitrogen heterocyclic compounds whose rings combine a phosphazene or phosphazane unit... 

The fourth chapter Selected Five-Membered Phosphorus Heterocycles Containing a Stereogenic Phosphorus presents the description of the synthesis and use of these compounds in a few asymmetric syntheses. 

Organophosphorus compounds are important intermediates in organic synthesis and have been widely used as pharmaceutical [1-6], agricultural [7], and chemical agents [8-14], Recently phosphorus heterocycles [15,16] have received considerable interest... 

The unique combination of double bonds in the molecules of those compounds, each with different reactivity along with the easy preparation, makes phosphorylated allenes useful substrates for the synthesis of different cyclic and noncyclic organophosphorus compounds. Recent investigations increase the scope of application of phosphorylated allenes as precursors in organic syntheses. Most of them are accompanied by the formation of five- or six-membered phosphorus heterocycles, which in many cases demonstrate certain biological activity. 

The configurations at phosphorus in compounds 73-76 were assigned on the basis of II-NMR data assuming that in phosphorus-containing heterocycles, the protons in a 1,3-m-relation to a P=0 group are deshielded. Thus, since H4 and H5 resonate at lower field in compounds 73a-76a than in compounds 73b-76b, the P=0 group must be cis to H4 and H5 in the a series [32]. These assignments were fully supported by the crystal structure studies of 75a, which showed that this... 

Phosphorus heterocycles 246 derived from hydroxyphenyl benzimidazole and aminophenyl benzimidazole undergo oxidative cycloaddition with 3,5-di-/fV/-butyl-l, 2-bcnzoquinonc to give a mixture of 247 and 248 (Equation 60) <2004HAC307, 2004HAC321>. Oxidative addition of ort o-chloranil to bis- and tetrakis-cyclodiphos-phazene compounds gives bis- and tetrakis-spirophosphoranes, for example, 41 (Equation 61). 

Although phosphorus trisulfide (P4S6—but see below) and phosphorus pentasulfide (P4S10) have been widely used in the preparation of heterocyclic compounds there is no recent review. Weintraub has given an account of solvent- and temperature-dependent reactions of the pentasulfide, the compound employed in almost all recently reported work.118... 

Thus, existing methods give the possibility of obtaining various heterocyclic compounds containing the P—C—O—B fragment with phosphorus and boron atoms being in a different coordination. 

Thioamides and their use in the preparation of the heterocyclic compounds are widely reported in the literature. Also they attract considerable interests in peptide chemistry. Molecular and crystal structures of some thioamide derivatives have been confirmed by X-ray diffraction data.8 10 Lawesson s reagent or phosphorus pentasulfide (P4S10) is actively used for the synthesis of thio-carbonyl compounds. Their preparation methods, reactions, applications in the synthesis of heterocycles and biological effects are mainly described in this section. 

A very large number of heterocyclic compounds are known consisting solely of phosphorus and chalcogen atoms, as well as those containing phosphorus, chalcogen and carbon or other hetero atoms. Such heterocycles have been the subject of several reviews2,83,84 and the discussion here will be limited to some representative examples of these compounds. 

In fact, a single series of phosphorus-based heterocyclic compounds, l,3-azaphospholo[5,l- ]isoquinolines (435 X = P), was reported together with their preparation through 1,5-electrocyclization of bis-(A-pyridinium ylidyl)phos-phenium chlorides 437, as shown in Scheme 113 <1999TL1565>. 

The phosphorus heterocycle (13) has been characterized23 by a reaction with trimethylsilyl azide. Other aminophosphines have been used as precursors of phosphazenes because of interest in the physiological properties of the latter compounds.24... 

This type of compound (152 to 155) containing one Pni, or tetra- and penta-coordinated Pv atom have been described.(1967,138anai39 1968,123 1969, ii6) Heterocycles with two P-heteroatom bonds in the ring have been more commonly reported. In addition to the numerous Pv oxyphos-phoranes and homologs, synthetised by Ramirez and co-workers (see 1968,124 for a review of these compounds) and by others,(1967,121,140 and 141 1969,147) parent tri-, tetra- and penta- coordinated phosphorus heterocyclics with various structures (156 to 162) are known.<1965,32 ... 

---