The reaction of N-trimethylsilyl-amides and -lactams with dimethyl(chloromethyl)chlorosilane. Kinetically controlled formation of (NSi) chelate intermediates, O-[(dimethylchlorosilyl)methyl]imidates and their rearrangement to final(OSi) chelate N-[(dimethylchlorosilyl)methyl]amides and lactams

Pentacoordinate hydrochlorosilanes with lactamomethyl ligand

“…It follows from the 1 H NMR spectrum of the crude reaction mixture which shows two sets of resonance with similar chemical shifts. The minor and major components were assigned to the (N-Si) and (O-Si) chelates (7 and 6, respectively) by comparison of their 1 H, 13 C and 29 Si NMR data with those for (NSi) and (O-Si) dimethyl(chloro)silylmethyl chelates [23]. Compound (8) with the O-Si coordinate bond was obtained as the sole product from similar reaction of benzyl substituted silane (4) with (1).…”

Reaction of N-trimethylsilyl derivatives of amides and lactams with chloro(chloromethyl)dimethylstannane: Crystal and molecular structure of 1-(chlorodimethylstannylmethyl)-2-piperidone

“…Similar to their silicon [6] and germanium [7] analogs, tin derivatives 2b,c and 3b,c can be characterized in the IR spectra by the adsorption bands at $1655 (average intensity) of the C@N adsorption and $1590 and 1500 cm À1 (strong) of the NCO fragment. In the IR spectrum of the solution of N-TMS-caprolactam and ClCH 2 SnMe 2 Cl in an inert solvent (o-xylene), both types of these absorptions were found to appear simultaneously at 80-100°C.…”

“…NMR monitoring data indicate that the first step is a transmetallation reaction producing Me 3 SiCl [6]. In the case of ClCH 2 SiMe 2 Cl [M = Si], the transmetallation step is rapid, and is complete within a few minutes even at low temperatures (from À60 to À80°C).…”

“…As part of a systematic study of hypervalent silicon [2], germanium [3], and tin [4] derivatives containing N-amidomethyl and N-lactamomethyl C,O-chelating ligands, we have shown earlier that the reaction of N-trimethylsilyl (N-TMS) derivatives of amides and lactams with ClCH 2 MMe 2 Cl (M = Si, Ge) [5] proceeds through more than one step [6]. NMR monitoring data indicate that the first step is a transmetallation reaction producing Me 3 SiCl [6].…”

Pentacoordinated chlorosilanes with C,O-chelate ligands derived from N-methyl-N'-organosulfonyl-prolinamides*

“…We may assume that the product of N-dimethylchlorosilylmethylation at the amide nitrogen atom, chlorosilane A (or/and its N'-TMS derivative using hexamethyldisilazane) is initially formed in these reactions and then undergoes thermal decomposition with the loss of HCl (respectively, Me 3 SiCl) during fractionation, leading to the desired silacyclane (S)-4. The IR spectrum of silacyclane (S)-4 features a stretching vibrational band for the NCO group at ~1640 cm -1 , while its 29 Si NMR spectrum shows a silicon chemical shift (~4 ppm) typical for the tetracoordinated silicon atom in a comparable environment [4,[24][25][26].…”