Arsine tris phenyl

A. Preparation.—The first reverse Wittig olefin synthesis has been reported. Triphenylphosphine oxide and dicyanoacetylene at 160 °C gave the stable ylide (1 78%) the reaction was reversed at 300 °C. No comparable reaction was observed with a variety of other activated acetylenes but tri phenyl arsine oxide gave the corresponding stable arsoranes with dicyanoacetylene (— 70 °C), methyl propiolate, hexafluorobut-2-yne, dimethyl acetylene dicarboxylate, and ethyl phenylpropiolate (130 °C). 

It has been found that while the aliphatic arsines and phenyl carbylamine chloride produce a similar turbidity at high concentration (4%), other substances such as mono-, di- and tri-chloromethyl chloroformates, chloropicrin, benzyl bromide, acrolein, the aromatic arsines, thiodiglycol, etc., do not react. 

The short As—O separations noted above are also found in triarylarsine oxides and the value in Ph3AsO (1.65 A) has been ascribed to the presence of one a and two n bonds. As—O distances in both the triclinic and hexagonal modifications of tri( p-chloro-phenyl)arsine oxide (1.64 A) and in (MeOjCCgHJEtjAsO (1.651 A) are similar. 

The arsinic acid (182) in the presence of ppa cyclizes with the phenyl ring to give the arsatriptycene oxide (181 Y = O). The reaction of tris(perfluorophenyl)arsine with arsenic trichloride gave di-arsatriptycene (187 M = As) in a 40% yield. Cyclization reactions which involve the generation of electrophilic metalloid centers have not been studied to any extent. 

When triphenylarsine in xylene is heated with hydrogen (60 atm) benzene and arsenic are produced 267). Raney nickel cleaves tri-(a-naphthyl)arsine and triphenylarsine yielding binaphthyl and biphenyl respectively 265). Nickel-aluminum alloy in aqueous alkali gives aniline from arsanilic acid 268), and sodium amide in boiling piperidine cleaves benzenearsonic acid 269). Phenyl groups are also lost from triphenylarsine when this is irradiated with thermal neutrons 270). 

CgtHMAsN, Tris-(4-dinietlvls>mino-phenyl]-arsin 14,843,1434, H424. 

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