Organometallic Complexes of Phospholes and Analogs

The half-sandwich and sandwich complexes of phospholides and phosphole tetramer are known even for the nontransition metals. The half-sandwich arrangement was studied for lithium tetramethylphospholide [89AG(E)1367] and sodium derivative 127 generated from the phospholide tetramer and sodium in the presence of 1,2-dimethoxyethane [94JA3306 96AG(E)1125]. Potassium and 1,2-dimethoxyethane in THE in these conditions give a full dianionic sandwich 128. 

Organomagnesium derivatives have not so far been isolated [80JA994 80JOM(193)C13]. Bis[bis(trimethylsilyl)phosphonamide] with diphenylbutadi-yne and calcium or strontium in THE yields the r (P)-coordinated species 129. Reaction of (THF)4Ba[P(SiMe3)2]2 with diphenylbutadiyne gives an T] -coordinated species 130 (98JA6722). 1-Chloro- and l-cyclopentadienyl-3,4-dimethyl-2,5-bis-(trimethylsilyl)-l-phosphacyclopenta-2,4-dienes both react with calcium to give 

131 (990M2491). l-Chloro-3,4-dimethyl-2,5-bis(trimethylsilyl) arsole is reduced by calcium to give dimer 132. 

Lithium 3,4-dimethylphospholide with Cr(CO)5(THF) gives 145 and then with methyl iodide, 146 (M = Cr, rXrXrXmc, 

93BSCF695). Complex 146 (M = Cr, r = rX R = Me, R = rX h) under-goes protonation to give finally the 27/-phosphole species 147. In contrast, the same phospholyllithium salt with W(CO)5(THF) yields 148. It can be reprotonated 

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