Synthesis of Tetraphenyl-stannacyclopentadienes (Stannoles). II. Derivatives and Adducts of 1,1-Dihalo-2,3,4,5-tetraphenylstannoles

摘要

1,1-Dibromo- and 1,1-diiodo-2,3,4,5-tetraphenyl-1-stannacyclopentadiene, dihalotetraphenylstannoles, XYSnC4(C6H5)4, can be derivatized to form a series of disubstituted products in which X=Y=N3, iso-NCO, iso-SCN, OC(O)CH3, SC(S)N(C2H5), N(CH3)2 and P(C6H5)2. Fluorination by KF in acetone results in the X=F, Y=Br or Y=I product only, and lithioamination by LiN(Si(CH3)3)2 yields the X=N(Si(CH3)2, Y=Br product only. Attempted synthesis of the dihalostannoles by halogenation of the intermediate tin(II) stannole from 1,4-dilithio-1,2,3,4-tetraphenyl-1 3-butadiene and tin(II) chloride yields only the ring-opened products (4-bromo-1,2,3,4-tetraphenylbutadienyl) tin tribromide or (4-iodo-1,2,3,4-tetraphenylbutadienyl)tin triiodide. Even gentle chlorination of hexaphenylstannole by elemental chlorine cleaves the ring tin-carbon bonds to form cis-cis-1,4-dichloro-1,2,3,4-tetraphenylbutadiene-1,3 and diephenyltin dichloride, while the action of a glacial acetic acid/acetic anhydride mixture yields tetraphenylfuran and diphenyltin diacetate. The dihalostannoles form neutral adducts with pyridine, 2,2'-bipyridyl and 1,10-phenanthroline, and the double salt (XSnC4(C6H5)4 terpy) + (X2YSnC4(C6H5)4) from 2,2',2 in.-terpyridine where X=Y=Br, I=F, Y=I. The structures of the substituted stannoles and the adducts of the dihalostannoles are discussed on the basis of tin-119m Mossbauer and infrared spectroscopic evidence. (Author)