Arsabenzenes synthesis

The synthesis of the first arsabenzene, 9-arsaanthracene, 6, was simultaneously communicated by Bickelhaupt16) and Jutzi17> in 1969. The elimination of hydrogen chloride from 9,10-dihydroaarsanthracene 7 afforded 6. These precursors are available from either reduction of the corresponding arsinic acids 816,18) or by the exchange reaction of dihydrostannaanthracenes 9 with arsenic trihalides 17). 

The successful conversion of 9 to 6 provided the original inspiration for the synthesis of the parent arsabenzene 2. The stannohydration of 1,4-pentadiyne 14 with dibutyl-tin dihydride furnished the necessary organotin precursor 1523). The exchange... 

A general synthesis of substituted arsabenzenes has been formulated from the arsacyclopentadiene derivative. The method requires generation of a carbene in the a position on the metal side chain followed by insertion of the carbene into an As—C ring bond (240) ... 

Chem., 1981, 217, 333). The molecular structure of arsa- and phospha- benzene has been determined by analysis combining electron diffraction and microwave data (T.C. Wong and L.S. Bartell, J. mol. Struct., 1978, 44, 169) and by nmr studies (Wong and Ashe, -ibid., 48, 219). Electron transmission spectroscopy has been employed to study temporary anion formation in arsabenzene (see p. 24)- For the synthesis of substituted arsabenzenes see S.T. Abu-Orabi (Diss. Abs. Int. B, 1982, 3, 1846) for the synthesis and electronic structure of arsa- and phospha-benzene see W.-T. G. Chan (ibid., 1978, 38, 5375) and for a review of arsa- and phospha-benzene see Markl (Chem. Unserer Zeit., 1982, 16, 139). 

An interesting case of ring expansion of a five-membered heterocyclic carbene is the reported synthesis of the arsabenzene (354) from the carbene 353 (generated from the corresponding sodium chloroacetate at 140°C) (Eq. 103).389... 

Since 1965 arsenic chemistry and especially the chemistry of heterocyclic arsenic compounds has become revitalized because of the synthesis of the first six-membered, cyclic conjugated, Hiickel-aromatic phosphabenzenes (2) and arsabenzenes (3) <71JA3293>. Then, 50 years after the salvarsan period, a second boom in arsenic chemistry, especially in heterocyclic, unsaturated arsenic compounds began. 

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