The Structure of Silylated Amides: N-Methyl-N-Trimethylsilyltrifluoroacetamide, a Reassignment of structure

Hydrosilanes Are Not Always Reducing Agents for Carbonyl Compounds but Can Also Induce Dehydration: A Ruthenium‐Catalyzed Conversion of Primary Amides to Nitriles

“…to 2a ) in the presence of 1 (2.5 mol‐%) in [D 6 ]benzene at 70 °C, the N–H protons of amide 2a were completely consumed within 1 h, and the 29 Si NMR spectrum of the reaction mixture showed four signals at δ = 10.1, 14.0, 15.7, and 23.9 ppm. These signals are the same as those for the bis‐silylated compounds prepared from p ‐toluoyl chloride and lithium 2,4‐bis(dimethylsilyl)‐1‐azacyclopentane according to the literature methods8 and support the presence of both N , N ‐ and O , N ‐silylated species 9. As the reaction progressed, 1 H resonances from p ‐tolunitrile and a 29 Si signal at δ = 8.59 ppm from 2,5‐bis(dimethylsilyl)‐1‐oxacyclopentane arise.…”

Palladium Complex Catalyzed Acylation of Allylic Esters with Acylsilanes

“…The product is only β , γ -unsaturated ketone, and no α , β -unsaturated isomers were detected. 29 Si NMR measurement of the resulting reaction mixture after the reaction confirmed a comparable formation of CF 3 COOSiMe 3 ( 5a : 33.6 ppm, lit . 33.1 ppm), indicating the Me 3 Si moiety of 1a effectively trapped the CF 3 COO leaving group from 2a .…”

Pentacoordinate hydrochlorosilanes with lactamomethyl ligand

“…The 15 N NMR resonance for chelate (7) is shifted upfield relative to the range typical of O-silylated imidates [25] that is due to the formation of the N-Si intramolecular dative bond. For chelate (6) the 15 N signal (245.4 ppm) is shifted in lower field as compared with that of piperidone-2 (114 ppm) because of increased p-character of the N-C bond in amide-type chelates [13].…”

“…As was shown previously, silylated amides and lactams can exist in the N-and O-tautomer forms (Scheme 2, A and B structure, respectively). Their ratio depends on the electronic and steric effects of the substituents at silicon [25][26][27]. Compound (1) as well as the transsilylation product A (R = X = Me) have N-tautomer structure in CH 2 Cl 2 and CHCl 3 solutions [4,23,28].…”