Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Polish Journal of Chemistry

2 2003

Powiadomienia systemowe

Sesja wygasła!
Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Synthessi of 3-Benzyl-1,3-thiazolidines by {2+3}-Cycloaddition of Sonochemically Generated Azomethine Ylides with Thiocarbonyl Compounds

Gebert A., Linden A., Mlostoń G., Heimgartner H.

Polish Journal of Chemistry

2003

Vol. 77 / nr 7

867-879

Sonification of N-benzyl-N-(methoxymethyl)-N-[(trimethylsilyl)methyl]amine (5a) in the presence of LiF led to the formation of the reactive azomethine ylide 1d, which was intercepted by cyclic thioketones to give spirocyclic 1,3-thiazolidines. In the case of 2,2,4,4-tetramethylcyclobutane-1,3-dithione (13), the 1:1- and 1:2-cycloadduct, respectively, was formed as the major product depending on the ratio of the starting materials. With 1,3-thiazole-5(4H)-thiones, 1d undergoes stereoselective [2+3]-cycloadditions with the C=S group to yield spirocyclic 1:1-adducts. In the case of the 1,3-dipole generated from N-benzyl-N-(methoxymethyl)-N-[1-(trimethylsilyl)ethyl]amine (5b), the [2+3]-cycloaddition proceeded in a non-regioselective manner leading to a mixture of regio- and diastereoisomers.

Synthesis of N-Unsubstituted 1,3-Thiazollidines by [2+3]-Cycloaddition of an Azomethine Ylide with Thiocarbonyl Compounds

Gebert A., Linden A., Mlostoń G., Heimgartner H.

Polish Journal of Chemistry

2003

Vol. 77 / nr 2

157-167

1,3-Dipolar cycloadditions of azomethine ylides with thiocarbonyl compounds have been used for the preparation of N-unsubstituted 1,3-thiazolidines. The reactive 1- phenyl-N-(trimethylsilyl)azomethine ylide (1c) was generated in situ by treatment of N-(benzylidene)[(trimethylsilyl)methyl]amine (6) with trimethylsilyl triflate and CsF in HMPA. All cycloadditions proceeded non-regioselectively, which led to mixtures of 4-phenyl- and 2-phenyl-substituted 1,3-thiazolidines.