L. P. Safronova

One-Pot Synthesis of 3-(Trimethylsilyl)propynamides

A highly efficient one-pot procedure was developed for the synthesis of 3-trimethylsilylpropynamides by acylation of amines with trimethylsilylpropynoyl chloride generated in situ. Selective N-acylation and N,O-bis-acylation of ß-amino alcohols with formation of, respectively, N-(hydroxyalkyl)propynamides and 2-methyl-2-[3-(trimethylsilyl)propynoylamino]propyl 3-(trimethylsilyl)propynoate were accomplished with high yields.

Highly efficient desilylation of 3-trimethylsilylprop-2-ynamides by the action of KF-Al2O3

A highly effective procedure has been developed for desilylation of 3-trimethylsilylprop-2-ynamides in the presence of KF-Al2O3 as catalyst. The corresponding terminal prop-2-ynamides were obtained in high yield in methanol at 25°C using 5 mol % of the catalyst (reaction time 20 min). Rise in temperature leads to the formation of Z,E-3-methoxyprop-2-enamides or 3,3-dimethoxypropanamides as a result of tandem desilylation-addition of methanol, depending on the conditions.

Efficient tandem synthesis of 3-alkylaminoprop-2-enamides from 3-trimethylsilylprop-2-ynamides

A tandem synthetic approach to previously unknown 3-aminoprop-2-enamides has been developed. It is based on Si-Csp desilylation of 3-trimethylsilylprop-2-ynamides and subsequent addition of an amine to the triple bond of intermediate terminal propynamides. The effects of the reaction conditions and amine nature on the efficiency of the process have been studied.

Synthesis of N-(3-Trimethylsilyl-2-propynoyl) Amino Acids

An efficient procedure has been developed for the preparation of previously unknown N-(3-trimethylsilyl-2-propynoyl) amino acids. The procedure is based on the reaction of 3-trimethylsilyl-2-propynoyl chloride with silylated amino acids which are generated in situ.

Reaction of Trimethylsilylpropiolyl Chloride with Diamines and 2-Aminoethanethiol

Reaction of 3-trimethylsilyl-2-propiolyl chloride with ethylenediamine and hexamethylenediamine provided previously unknown bis(trimethylsilylpropiolyl)amides. Reactions of the acyl halide with 1,2-phenylenediamine and 2-aminoethanethiol proceeded regioselectively at a single reaction center to furnish amino- and thioamides of trimethylsilylpropiolic acid.

Distortion of Configuration of the Nitrogen Atom in 3-Trimethylsilylpropynamides

Analysis of the IR spectral parameters and the results of AM1 quantum-chemical calculations indicated distortion of the planar structure of the amide fragment and destabilization of the nitrogen configuration in new N-functionalized 3-trimethylsilylpropynamides Me3SiC≡CC(O)NHR. This effect is most pronounced in N-hydroxy-3-trimethylsilylpropynamide upon formation of intramolecular hydrogen bond C=O···H-O.

Molecular and Electronic Structure of Trimethylsilylpropiolamides

The specific features of molecular and electronic structure of trimethylsilylpropiolic acid amides were studied by means of IR spectroscopy and quantum chemistry (AM1). The competition between p,π-conjugation in the amide fragment and π,π-conjugation in the ethynylcarbonyl group C≡C-C=O was established. The prevailing conformers were revealed, their geometrical parameters were established, the barriers to internal rotation around the amide C-N bond were calculated for acyclic (13 kcal mol-1) and heterocyclic (8.12 kcal mol-1) amides.