31934-34-6Relevant articles and documents
Adamantanethione and diazomethane; dual regiochemistry of cycloadditions [1]
Huisgen,Mloston
, p. 635 - 644 (2007/10/03)
Cydoaddilions of diazoalkanes to thiones take place in two directions furnishing 1,3,4-thiadiazolines and/or their 1,2,3-isomers, depending upon the substituents. Adamantanethione and diazomethane give rise to hoth regioisomers; a literature report on the high solvent dependence of the isomer ratio is confirmed, and the two regioisomers are isolated. The 1,3,4-thiadiazoline 20 eliminates N2 at 80°C (t1/2 55 s) in a 1,3-dipolar cycdoreversion: the thiocarbonyl ylide 22 generated undergoes electrocyclization, forming a thiirane, or is intercepted by reactions with HX (thiols, alcohols) or dipolarophilic multiple bonds. The N2 extrusion from the isomeric 1,2,3-thiadiazoline 21 is at 80°C 600 times slower: the formation of the spirothiirane and homoadamantane-2-thione is explained by a diazonium thiolate as an intermediate.
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.