Newer Developments in the Area of Penta- and Hexaorganyl Arsenic Compounds

9 Newer Developments in the Area of Penta- and Hexaorganyl Arsenic Compounds 

2 -biphenylylene-triphenylarsorane 115 could be prepared along two ways, either with 5-phenyldibenzarsole tosylimine 114 and phenyllithium or with triphenylarsine tosylimine 116 and 2,2 -dilithiobiphenyl 121,122). Likewise, the spiro-arsoranes 117, 118 were synthesized in high yields, 118 being rather unstable, probably because of unfavorable steric interactions at the reverse of the benzo-biphenyiylene ligand121). 

for these compounds, names emphasizing the arsorane nature, e.g. bis-2,2 -biphenylylenearylarsorane for 117, or names evaluating more the heterospirocyclic skeleton, e.g. 5 -(4-dimethylaminophenyl)spiro[l 1 H-benzo[b]naphth[2,1 -djarsole-ll,5 -[5 //]dibenzarsole] for 118 are possible. 

A still better synthesis for such spiroarsoranes was finally found in the reaction of the bis-2,2 -biphenylylenearsonium ion 120 (5,5 -spirobi[5f7-dibenzarsolium]) with a variety of organyllithium or Grignard reagents 121 123 , 120 being readily accessible from appropriate chlorinated arsine precursors 119a, b 121). 

R= Alkyl122,1231 Me Et CD2Me i-Pr n-Bu t-Bu Cyclopentyl Benzyl Neopentyl PhMe2CCH2 

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