Cyclic phosphonate esters, structure

Other Studies. - The P NMR chemical shifts of alcohols, carboxylic acids and phenols phosphitylated with 2-chloro-4,4,5,5-tetramethyl-dioxaphospholane have been correlated with substituent effects of phenols. P NMR spectroscopy has also been used to study activation pathways of aryl H-phosphonate ester condensation reactions, the conversion of allenyl and divinyl phosphines to 1- and 2-phosphadienes, the reaction of tetraphosphorus decasulfide with dialkyl disulfides, the reaction of phosphine with cyclic olefins, the chemical shift tensors of powder samples of phosphole derivatives, the reactions of alcohols and mercaptans with tetraphosphorus trichalcogen diiodides, the structure of aminomethanebisphosphonic acids, and reactions of 00-di-(2-ethylhexyl)dithiophosphoric acids. ... 

A series of D,D-dialkyl 2-oxo-2- 4-(selenomorpholinosulfonyl)phenyla-mino) ethylphosphonates (37) has been synthesized and their structures confirmed by IR, H and P NMR spectroscopy and mass spectrometry. Other papers on phosphonate esters have used principally H and C NMR spectroscopy including a facile diastereoselective synthesis of phosphonate esters bearing cyclic or acyclic amides and a study of structural isomers of pyridinephosphonic acids. Some novel iminophosphoranes have been synthesized and characterized by IR, NMR ( H, C and and solely H NMR in addition to mass spectroscopic analysis. The crystal synthesis, structure (by XRD) and characterization of a new organic... 

A number of phosphonate and phosphinate derivatives where the phosphorus atom is directly bonded to non-aromatic cyclic systems have been reported. The synthesis and reactions of a number of compounds with the general structure 103 have been reported. Enantiomerically pure cyclopropanephosphonic acids which are constrained analogues of the GABA antagonist phaclophen, have been prepared by stereocontrolled Michael addition of a-anions derived from chiral chloromethylphosphonamides 104 to a,P-unsaturated esters followed by in situ cyclisation. Other asymmetric syntheses include those of (/ )- and (S)-piper-idin-2-ylphosphonic acid (105) via the addition to trialkyl phosphites to iminium salt equivalents and 4-thiazolidinylphosphonate 106 by catalytic asymmetric hydrophosphonylation of 3-thiazoline. In the latter case both titanium and lanthanoid (which give much better e.e. values) chiral catalysts are used. 

Cyclic monomers that have been polymerized via ring-opening encompass a variety of structures, such as alkanes, alkenes, compounds containing heteroatoms in the ring oxygen [ethers, acetals, esters (lactones, lactides, and carbonates), and anhydrides], sulfur (polysulfur, sulfides and polysulfides), nitrogen [amines, amides (lactames), imides, N-carboxyanhydrides and 1,3-oxaza derivatives], phosphorus (phosphates, phosphonates, phosphites, phosphines and phosphazenes), or silicon (siloxanes, silaethers, carbosilanes and silanes). For the majority of these monomers, convenient polymerization conditions have been elaborated, that result in the controlled synthesis of the corresponding polymers [1-13]. 

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