Hydrosilylation in Aryliminopyrrolide‐Substituted Silanes

Abstract

A range of silanes was synthesized by the reaction of HSiCl3 with iminopyrrole derivatives in the presence of NEt3 . In certain cases, intramolecular hydrosilylation converts the imine ligand into an amino substituent. This reaction is inhibited by factors such as electron-donating substitution on Si and steric bulk. The monosubstituted ((Dipp) IMP)SiHMeCl ((Dipp) IMP=2-[N-(2,6-diisopropylphenyl)iminomethyl]pyrrolide), is stable towards hydrosilylation, but slow hydrosilylation is observed for ((Dipp) IMP)SiHCl2 . Reaction of two equivalents of (Dipp) IMPH with HSiCl3 results in the hydrosilylation product ((Dipp) AMP)((Dipp) IMP)SiCl ((Dipp) AMP=2-[N-(2,6-diisopropylphenyl)aminomethylene]pyrrolide), but the trisubsitituted ((Dipp) IMP)3 SiH is stable. Monitoring the hydrosilylation reaction of ((Dipp) IMP)SiHCl2 reveals a reactive pathway involving ligand redistribution reactions to form the disubstituted ((Dipp) AMP)((Dipp) IMP)SiCl as an intermediate. The reaction is strongly accelerated in the presence of chloride anions.

Organosilicon and ‐germanium Hydrides in Catalyst‐Free Hydrometallation Reactions

“…A similar situation was also found when the iminopyrrole DippIMPH was deprotonated with n BuLi and the obtained DippIMPLi was treated with HSiCl 3 or HSiMeCl 2 to give unreduced CH=N→Si coordinated monosubstituted (aryliminopyrrolido)silanes (Scheme ) …”

“…The hydrosilylation of monosubstituted silane (DippIMP)SiHCl 2 ( 22 ) was monitored by NMR spectroscopy, which provided evidence of a complex reaction pathway including a ligand‐redistribution process followed by intramolecular hydrosilylation and a further final ligand‐redistribution process (Scheme ) …”

Synthesis of High Molecular Weight Vinylphenyl-Con Taining MQ Silicone Resin via Hydrosilylation Reaction

“…In terms of the VPMQ, the characteristic absorption peaks of the C-H group on Si-C 6 H 5 also appear at 3080, 800, 756 and 702 cm −1 [27]. Furthermore, the symmetric stretching vibrations of C-H on Si-CH 2 -CH 2 -Si bridges formed during the hydrosilylation reaction appear at 2870 cm −1 [28], and the characteristic absorption peak at 1010 cm −1 attributed to Si-O-Si introduced by PDPS can be seen. Moreover, the characteristic absorption peak of Si-CH=CH 2 at 1600 cm −1 is significantly weakened, and the absorption peak of Si-H at 2134 cm −1 is absent.…”

Synthesis of N-Heterocycle Substituted Silyl Ligands within the Coordination Sphere of Iron

“…As the imine functionality in Dipp IMP is susceptible to intramolecular hydrosilylation, the corresponding hydrosilanes are unsuitable precursors for silyl complexes via either deprotonation or oxidative addition. 57 Dipp IMPH was synthesized according to the literature procedure, 104 followed by deprotonation using NaHMDS. Reaction of either two or three equiv of Dipp IMPNa with 1 formed the same compound 10 , while reaction of 1 equiv of Dipp IMPNa with 1 afforded a mixture of compounds containing both 1 and 10 .…”