Phosphorus containing heterocycles

RETENTION INDICES OF HETEROCYCLIC PHOSPHORUS-CONTAINING DERIVATIVES OF ALCOHOLS [43]... 

Coordination compounds with three-, four-, and six-member phosphorus-containing heterocycles 98PAC819. 

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... 

Depending on the relative amount of reagents, three types of products may be obtained in the reaction of hydroxymethylphosphines with amines acyclic aminomethylphosphines, 1,3,5-diazaphosphorinanes, and 1,5,3,7-diazadiphosphacyclooctanes. Indeed, the interaction of phosphorus-containing diols with 1 mol of amine gives eight-membered heterocycles. The initial assumption about the formation of 1,3-azaphosphetidines... 

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. 

Diathiadiphosphetane disulfides are probably the most studied and the most thermally and hydrolytically stable of all the phosphorus-chalcogen heterocycles. They contain a central four membered P2S2 ring and can be prepared from heating phosphorus pentasulfide with aromatic compounds. The most well-known of these is Lawesson s reagent (43), which is made from anisole and phosphorus pentasulfide,92 and is used extensively in organic synthesis procedures (see Section 5.4.1). Other dithiadiphosphetane disulfides of note are 44 and 45, formed from the reaction of phosphorus pentasulfide with ferrocene or 1 -bromonaphthalene respectively.93... 

Two types of phosphorus-containing five-membered heterocycles - both entirely new and not referred to in CHEC-11(1996) - have been synthesized during the past years. These syntheses are summarized in Scheme 35. 

Studies on the synthesis of [l,2,4,3]triazaphospholo[l,5-tf]pyridines have been reported by Schmidpeter et al. <1993JPR458, 1994PS381, 1995ZNB558>. The reaction pathway starts from 2-aminopyridine 147 which is first subjected to an Anamination reaction to give 1,2-diaminopyridinium iodide 148, and this compound is treated with tris-dimethylaminophosphine to yield the five-membered phosphorus-containing heterocycle 149. 

Recently novel information on cyclizations to phosphorus-containing heterocycles with heteroatomic arrangement has appeared. These ring closures are shown in Scheme 46. 

Two phosphorus-containing ring systems and one silicon-containing fused heterocycle belonging to the hetero-atomic arrangements of this chapter have been synthesized recently. The synthetic pathways are presented in Scheme 25. 

Synthesis of two phosphorus-containing heterocycles with the heteroatom arrangement of this chapter has been elaborated during the past years. 

Synthesis of the other phosphorus-containing heterocycle, pyrazolo[l,5-c][l,3,5,2]triazaphosphorine, has been published by Yang and Lu <1994SC59> (Scheme 20). 

The present volume comprises 17 chapters, written by 27 authors from 11 countries, and deals with theoretical aspects and structural chemistry of peroxy compounds, with their thermochemistry, O NMR spectra and analysis, extensively with synthesis of cyclic peroxides and with the uses of peroxides in synthesis, and with peroxides in biological systems. Heterocyclic peroxides, containing silicon, germanium, sulfur and phosphorus, as well as transition metal peroxides are treated in several chapters. Special chapters deal with allylic peroxides, advances in the chemistry of dioxiranes and dioxetanes, and chemiluminescence of peroxide and with polar effects of their decomposition. A chapter on anti-malarial and anti-tumor peroxides, a hot topic in recent research of peroxides, closes the book. 

Heterocyclic phosphorus ylides are a rather diverse and little known class of compounds. A variety of such structures are now known and in some cases these are of considerable synthetic value. In this chapter we have attempted to review all heterocyclic compounds containing one or more exocyclic phosphorus ylide functions, i.e. of general structure 1. It should be noted that in many cases these exist predominantly in the phosphonium ylide (P+—C ) form but for simplicity they are represented in the ylene form 1. Cyclic ylides 2 and 3 in which the phosphorus atom is within the ring are not included. 

Volume 1 covers primary, secondary and tertiary phosphines (PR3H3 , n= 1-3), polyphosphines (both P—(C) —P and R(P) R, n > 1) and heterocyclic compounds containing phosphorus. 

Table 1 Nomenclature of Heterocyclic Rings containing Phosphorus...

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