Formation of Silicon−Carbon Bonds by Photochemical Irradiation of (η⁵-C₅H₅)Fe(CO)₂SiR₃ and (η⁵-C₅H₅)Fe(CO)₂Me to Obtain R₃SiMe

Abstract

Photochemical irradiation of an equimolar mixture of (η 5 -C 5 H 5 )Fe(CO) 2 SiR 3 , FpSiR 3 , and FpMe leads to the efficient formation of the silicon-carbon coupled product R 3 SiMe, R 3 = Me 3 , Me 2 Ph, MePh 2 , Ph 3 , ClMe 2 , Cl 2 Me, Cl 3 , Me 2 Ar (Ar = C 6 H 4 X, X = F, OMe, CF 3 , NMe 2 . Similar chemistry occurs with related germyl and stannyl complexes at slower rates, Si > Ge> ≫Sn. Substitution of an aryl hydrogen in FpSiMe 2 C 6 H 4 R′ has little effect upon the rate of the reaction whereas progressive substitution of methyl groups on silicon by Cl slows the process. Also changing FpMe to FpCH 2 SiMe 3 dramatically slows the reaction as does the use of (η 5 -C 5 Me 5 )Fe(CO) 2 derivatives. A mechanism involving the initial formation of the 16e -intermediate (η 5 -C 5 H 5 )Fe(CO)Me followed by oxidative addition of the Fe-Si bond, accounts for the experimental results obtained.

Iron‐catalyzed depolymerization of polysiloxanes to produce dichlorodimethylsilane, diacetoxydimethylsilane, or dimethoxydimethylsilane

“…Dichlorodimethylsilane 3: 1 H NMR (200 MHz, CDCl 3 , 25°C): δ = 0.78 (d, 2 J Si , H = 7.60 Hz) ppm. 13 C{ 1 H} NMR (50 MHz, CDCl 3 , 25°C) δ = 6.7 (d, 1 J Si , C = 68.29 Hz) ppm.…”

(Cyclopentadienyl)dicarbonylmethyliron ((η5-C5H5)Fe(CO)2CH3, FpMe), a Seminal Transition-Metal Alkyl Complex: Mobility of the Methyl Group

“…The silicon−carbon-coupled products R 3 SiMe were released when equimolar amounts of FpSiR 3 and 1 were photochemically irradiated. The oxidative addition of the Fe−Si bond to the 16e [(η 5 -C 5 H 5 )Fe(CO)CH 3 ] species was suggested to be the key step in this chemistry: e.g., eq . The process was favored by the presence of electron-withdrawing substituents on silicon, and a similar chemistry was observed when FpGeMe 3 replaced the silyl derivative to produce GeMe 4 , at about the same rate.…”