INTRODUCTION Uff
This chapter deals with six-membered rings containing five carbons and one phosphorus and none, one or two double bonds and in which the smallest ring containing the heteroatom is six membered. Not surprisingly, such structures have been known for a long time and probably the first phosphorus-carbon heterocycle ever made was 1-phenylphosphinane lt 15CB1473 gt . As in all areas of phosphorus chemistry consistency of nomenclature leaves much to be desired. The IUPAC name for the parent ring,...
Rt
It has also been noted that, while stable at room temperature, a solution of triphenylphosphole in carbon tetrachloride undergoes a distinct color change yellow to red which is reversible on cooling lt 82CJC138 gt . Benzotrichloride also reacts on heating but the color change is not reversible. The phosphorus species formed in these reactions are not fully understood, but may stem from an initially formed phospholium salt, for example 64 Equation 2 . Azides have been found to attack the...
The Foundations
After the initial discovery of 1-phenylphosphinane by Griittner and Wiernik lt 15CB1473 gt Equation 1 , Griittner and Krause prepared 1-phenylphospholane using the same procedure lt 16CB437 gt . In 1920, Conant and Cook showed that phosphorus trichloride readily reacts with a, -unsaturated ketones to give 1,2-oxaphospholenes lt 20JA830 gt Equation 3 . Later, phosphorus trichloride was replaced by phenyldichlorophosphine lt 21JA1665 gt . With hindsight, this reaction is the forerunner of the...
O Dmo
The new phosphole 385 offers an enormous 4 2 -cycloaddition reactivity. With phosphaalkynes R-C P a sequence of 4 1 and 2 2 2 -cycloaddition reactions yields the oxatetraphosphadelta-cyclenes, which can be isolated by column chromatography as a mixture of 386 and 387 95-98 Scheme 122 . With DMAD 385 reacts at -20 C to 25 C via the 4 2 intermediate 388 , which undergoes a retro- 4 2 -reaction to furnish the labile 1,2-oxaphosphole 389 lt 99EJOC587 gt Scheme 122 . The phosphaalkynes react with...
Ring Systems With Three Phosphorus Atoms
The 1,3,5-triphosphinines are known as all- ,1 all-A.5 and mixed A3, -derivatives III, IV . The 1,2,3-triphosphinines I, II are only known as l . 2 -3,3 .5-system II . The 1,2,4-triphosphinines V, VI hitherto are described only as di- and tetrahydro systems. Treatment of 345 with an equimolar quantity of PCI3 in the presence of SnC affords the cyclic triphosphenium salt 346 . The SnCl2 acts as a reducing agent, being oxidized to SnCU which acts as a Cl acceptor to give the SnCl6 2 counterion...
PH Bvd
The 2 -phosphole moiety has also been stabilized by incorporation into some phosphaazulene derivatives synthesized in the Markl laboratory. The structures 208 , 209 , and 210 are shown in Equation 41 and Scheme 47. red solid m.p. 85-87 C 31P 8 177.9 blue-green oil 209 b.p. 120-125 C 102 mm 31P 5 170.6 green solid 208 m.p. 71.5 C 31P 8 174.8 green solid 208 m.p. 71.5 C 31P 8 174.8 These remarkable compounds were of good stability in fact the molecular ion was the base peak in the mass spectrum...
Info Ews
a In CgD . b Not assigned or not resolved. c C-l and C-3 are equivalent. d In pentane. e In THF. a In CgD . b Not assigned or not resolved. c C-l and C-3 are equivalent. d In pentane. e In THF. A similar shift was also observed in the tungsten pentacarbonyl complexes of the following phosphetane and 1,2-dihydrophosphetes. In these cases, the compounds resonate down filed in the order Me lt Ph lt i-Bu, which is attributable to inductive effect for Me and Ph and electronic repulsion between...
I Arh
60 , 8 31P 74.3 A , 53.6 B i 38.8 Hz 60 , 8 31P 74.3 A , 53.6 B i 38.8 Hz Simple alkyl halides give crystalline quaternary salts, although these seem to form more slowly than those of other cyclic phosphines lt 69JA3308 gt . They too will dimerize on formation or on heating lt 73J0C1954 gt but less readily so than oxides, so that some simple phospholium salts see Section 4.2.1.6.3 are known e.g. 61 , lt 73J0C1858 gt . Methylene iodide gives an iodomethyl salt 62 with 1,2,5-triphenylphosphole...
R Tdb
The P-P-bond of a l,2-dihydro-l,2-diphosphete derivative may be opened selectively by controlled hydrolysis and a phosphaalkene is formed lt 97JC gt C 62 7605 gt . 3.3.4.6 Reactivity of Ring Heteroatoms and Substituents Attached to Ring Heteroatoms Mono- or diprotonation of tetraphosphacubane or tricyclic l,2-dihydro-l,2-diphosphetes with superacids and monoalkylation or alkynylation with strong electrophiles leads to stable phosphonium salts lt 93JC C 58 4105, 95JC C 60 47, 95JC C 60 3149 gt ....
ANGELA MARINETTI and DUNCAN CARMICHAEL Ecole Nationale Suprieure de Chimie de
3.1.2 THEORETICAL METHODS 88 3.1.3 EXPERIMENTAL STRUCTURAL METHODS 88 3.1.3.1 X-Ray Diffraction Studies 88 3.1.3.3 IR Spectroscopy and Mass Spectrometry 91 3.1.4 THERMODYNAMIC ASPECTS 91 3.1.4.1 Physical Properties and Physical Constants 91 3.1.4.2 Conformational and Configurational Studies 92 3.1.5 REACTIVITY OF THE PHOSPHORUS ATOM AND SUBSTITUENTS ATTACHED TO THE PHOSPHORUS ATOM 93 3.1.5.1 Nucleophilic Displacement on Phosphetanium Salts, Phosphetane Oxides and Trivalent Phosphetanes 93...
Rha 1
G. David, E. Niecke and M. Nieger Tetrahedron Lett., 1992, 33, 2335. M.Y. Dmitrichenko, V.G. Rozinov, V.l. Donskikh, G.V. Ratovskii, V.G. Efremov and G.V. Dolgushin Zh. Obshch. Kkim., 1992, 62, 306 Chem. Abstr., 1993, 118, 169178 . C. Mtiler, T.G. Meyer, M. Farkens, R. Sonnenburg and R. Schmutzler Z. Naturforsch., 1992, 47B, 760. S.F. Gamper and A. Schmidbauer Chem. Ber., 1993, 126, 601. H.R. Alcock, S.M. Coley, I. Manners, K.B. Visscher, M. Parvez, O. Nuyken and G. Renner Inorg. Chem., 1993,...
I Voe
The Staudinger reaction between certain bis azides and bis phosphines has been used to prepare a variety of bis iminophosphorane -containing macrocycles containing 12 or more members under mild conditions lt 97JOM 529 l2l gt . For example, 210 and 211 X NH, O, n 1, 2 were isolated in 79-97 yield by this method. On the other hand, the reaction between 212 and 213 in diethyl ether at room temperature gave 214 in 66 yield a similar strategy with the corresponding TV-oxide of 212 in dichloromethane...
N H
L lone pair, O, S R organic group useful reactants. As the examples show, with some combinations of reactants the 3-phospholene system is favoured, but the intermediate cycloadduct and the 3-phospholene oxide can enter into rearrangement processes that lead to the 2-phospholene as the major product. Reaction mixtures are always dominated by one of the two regioisomers, and usually can be separated with ease. Some structural limitations in the McCormack cycloaddition do exist, however. Thus,...