The First Stable P-Phosphoranyl Substituted Phosphaalkene

Abstract

Interaction of bis(catechoI)chlorophosphorane (1) with two-coordinated phosphorus derivative (2) has been studied by dynamic ³¹P NMR method. The compounds react under soft conditions in methylene chloride with formation of phosphaalkene (5). the first stable representative of Pⁱⁱ-P^v structure derivatives.     

第一个稳定的单取代环己烷直立构象体

第一个稳定的单取代环己烷直立构象体ＦｉｒｓｔＳｔａｂｌｅＡｘｉａｌＣｏｎｆｏｒｍｅｒｓｏｆＭｏｎｏｓｕｂｓｔｉｔｕｔｅｄＣｙｃｌｏｈｅｘａｎｅｓ１．论文名称ＦｉｒｓｔＣｏｍｐｌｅｔｅｌｙＳｔａｂｌｅＡｘｉａｌＣｏｎｆｏｒｍｅｒｓｏｆＭｏｎｏｓｕｂｓｔ...     

First Representatives of Stable Phosphoranes Derived from Bicyclophosphorylated Carbohydrates

1,2-O-Isopropylidene--D-glucofuranose 3,5,6-phosphite was stidied in reactions with -dicarbonyl compounds. Reagents with the electron-acceptor halogen atom form with the former stable phosphoranes, while unsubstituted -dicarbonyl compounds, the corresponding normal phosphates.     

New Aspects of the Reactivity of the First Stable Germa-and Stannaphosphenes

Abstract

Various aspects of the reactivity of the first stable germaphosphene 1 and stannaphosphene 6 are described.     

Strong P=P pi Bonds: The First Synthesis of a Stable Phosphanyl Phosphenium Ion

A 35-fold excess of methyl triflate (2) is required to quantitively prepare 3, the first phosphanyl phosphenium ion, from diphosphene 1. Experimental data and calculations indicate that the P=P bond becomes stronger upon alkylation.     

The Chemistry of Stable Silabenzenes

Stable silabenzenes ( 1a; R = Tbt, 1b; R = Bbt) were synthesized by taking advantage of extremely bulky and efficient steric protection groups, 2,4,6‐tris[bis(trimethylsilyl)methyl]phenyl (Tbt) and 2,6‐bis‐[bis(trimethylsilyl)methyl]‐4‐[tris(trimethylsilyl)methyl]phenyl (Bbt). The structure of Tbt‐substituted 1a was determined by X‐ray crystallographic analysis, which demonstrated the complete delocalization of the π‐electrons of the silabenzene ring. It was found that silabenzene 1a reacted with C–C and C–O multiple bond compounds to give the corresponding [4+2]‐cycloadducts via 1,4‐addition, while 1a underwent both 1,2‐ and 1,4‐additions by the reaction with methanol. Silabenzene 1a dimerized very gradually to afford its [4+2]‐dimer, although 1b showed no change under the same conditions. Photochemical reaction of 1a gave the corresponding silabenzvalene isomer instead of the Dewar silabenzene isomer.