102970-99-0Relevant academic research and scientific papers
1,3-Dipolar cycloadditions, 117. Reactions of thiobenzophenone S- methylide with thiocarbonyl compounds
Huisgen, Rolf,Li, Xingya,Mloston, Grzegorz,Fulka, Claudia
, p. 1695 - 1702 (2007/10/03)
2,5-Dihydro-2,2-diphenyl-1,3,4-thiadiazole (4) eliminates N2 at -45 °C and generates thiobenzophenone S-methylide (5), which is intercepted by dipolarophiles. The 1,3-cycloadditions of 5 with thiones (aromatic and aliphatic thioketones, dithioesters, trithiocarbonate) furnish 1,3- dithiolanes 7, in which the substituents, even voluminous ones, appear in the proximal 4- and 5-positions. The reaction of 5 with adamant-anethione furnishes 7h and 4,4,5,5-tetraphenyl-1,3-dithiolane (7a) in a ratio of 4:1; a methylene transfer is involved, and the mechanistic pathways are discussed. The cycloadduct 7f originating from 5 and diphenyl trithiocarbonate undergoes an isomerization which consists of ionization and ring-opening leading to a ketene dithioacetal structure.
Cycloadditions of adamantanethione S-methylide to heteromultiple bonds
Mloston, Grzegorz,Huisgen, Rolf,Polborn, Kurt
, p. 11475 - 11494 (2007/10/03)
Adamantanethione S-methylide (5) is an easily accessible thiocarbonyl S- ylide. Generated by N2 elimination from the cycloadduct of adamantanethione and diazomethane, the nucleophilic 1,3-dipole 5 reacts in situ with thiocarbonyl compounds furnishing 1,3-dithiolanes. 5 and carbon disulfide afford 1:1 and 2:1 cycloadducts. The structures are assessed by NMR spectra, a X-ray analysis, and C-S hydrogenolyses. The C=S group is an ambident electrophile; the ratios of regioisomeric adducts suggest that electronic effects favor the 4',5'-substituted 1,3-dithiolanes, whereas steric effects support the 2',4'-substituted systems. Electrophilic carbonyl compounds and 5 regiospecifically provide 2,4-disubstituted 1,3-oxathiolanes. Imines appear to be weak dipolarophiles vs. 5.
SCHOENBERG REACTIONS OF ADAMANTANETHIONE S-METHYLIDE
Mloston, Grzegorz,Huisgen, Rolf
, p. 2201 - 2206 (2007/10/02)
Nitrogen extrusion from 1,3,4-thiadiazoline-2-spiro-2'-adamantane at 40 deg C generates the thiocarbonyl ylide of the title which is intercepted in situ by dipolarophiles with CS double bond (aromatic and aliphatic thioketones, dithiocarboxylic esters, carbon disulfide, phenyl isothiocyanate).Both cycloaddition directions are used in the 1,3-dithiolane formation; the structural dependence and orientational forces are discussed.
RECENT DEVELOPMENTS OF THE CHEMISTRY OF THIOCARBONYL YLIDES
Huisgen, Rolf,Fulka, Claudia,Kalwinsch, Ivars,Xingya, Li,Mloston, Grzegorz,at al.
, p. 511 - 532 (2007/10/02)
The cycloaddition of diazoalkanes to CS double bonds furnishes 1,3,4-thiadiazolines which give rise to thiocarbonyl ylides and N2 in cycloreversion.Thiocarbonyl ylides are nucleophilic 1,3-dipoles which are interceptible by thiones or electron-deficient alkenes and alkynes as dipolarophiles affording 1,3-dithiolanes, dihydrothiophenes and thiolanes, respectively.In the absence of reaction partners, thiocarbonyl ylides undergo electrocyclization, dimerization, β-H abstraction or Wagner-Meerwein rearrangement.
