Spirobicyclic phosphoranes

Spirobicyclic phosphoranes, reaction with hex-afluoroacetone, 30 236 Spirobicyclotriphosphazene, 21 110 Spirocyelic phosphoranes, 30 245 square-planar structure, 30 248 synthesis, 30 252... 

The reaction of a spirobicyclic phosphorane with HFA leads to the formation of the alcohol 38 (113). 

Methyl-1-methylenephosphorinane (7) reacts with oxirane and oxetane to form spirobicyclic phosphoranes (8 n = 3 and 4 respectively) (H. Schmidbaur and P. Holl, Ber., 1979, 112,... 

Spectroscopic data presented in an earlier report (1) were interpreted in terms of an apical P-H bond disposition and a trigonal bipyramidal (TBP) structure for a monocyclic triarylhydrido-phosphorane ( ). We have an X-ray crystallographic solution of the structure of apical hydridophosphorane as well as the structure of its diaryldialkoxy spirobicyclic analogue, Table... 

Pentacoordinate hydroxyphosphoranes are likely intermediates or transition states in substitution reactions at tetracoordinate phosphorus (1). Recently, stable hydroxyphosphoranes (2, 3) and their conjugate bases - metal phosphoranoxides (J, 5) have been isolated. Spectroscopic evidence (J - 7) for equilibria between P(IV) compounds and hydroxyphosphoranes have been reported. Observation (8) and isolation (9) of P(IV) TBP phosphoranide species have also been announced. All these phosphoranes are stabilized by several features dominated by their spirobicyclic nature. 

The continued interest in spirobicyclic derivatives indicated by the structures listed above is also reflected in theoretical contributions on the quantitative description of structural distortions of cyclic phosphoranes in terms of the Berry exchange coordinate157 and on computer simulation of phosphorane structures158. ... 

The synthesis of novel phosphorane structures continues to be fashionable. When methyl diphenylphosphinite is heated with 2-hydroxycinnamic acid, the spirobicyclic acyloxyphosphorane (79) is formed. (See also Chapter 2). The now well established reaction of the tervalent phosphorus with compounds containing two suitably... 

The tetragonal pyramidal configuration generally only occurs as a transition state in BPR. There are, however, just a few stable crystalline phosphoranes in which the tetragonal pyramidal configuration is found. These are spirobicyclic systems which contain very strained rings such as... 

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