41320-28-9Relevant articles and documents
Catalytic thione-thiol rearrangement of xanthates by 4- dialkylaminopyridine
Nakagawa, Hidetoshi,Eto, Masashi,Harano, Kazunobu
, p. 51 - 59 (2007/10/03)
Pyridines bearing electron-donating substituents are useful catalysts for the rearrangement of O,S-dialkyl xanthates (1) to S,S-dialkyl dithiocarbonates (2). The rearrangement was analyzed by semiempirical and ab initio molecular orbital methods. The transition-structure analyses indicate that the pyridine-ring nitrogen of dialkylaminopyridine rather than the dialkylamino nitrogen attacks the O-alkyl carbon of xanthates. The reaction proceeds through an S(N)2 mechanism to give the dithiolcarbonate anion (RSCOS-) which acts as an actual catalyst.
Thione-thiol rearrangement of xanthates catalyzed by pyridine N-oxides. Remarkably enhanced reactivity of 4-dialkylaminopyridine N-oxides
Harano,Nakagawa,Kamei,Kiyonaga,Hisano
, p. 1675 - 1682 (2007/10/02)
Pyridine N-oxides bearing electron-donating substituents (III) are efficient catalysts for rearrangement of O-alkyl S-methyl dithiocarbonates (xanthates) (I) to the corresponding S-alkyl S-methyl dithiocarbonates (dithiolcarbonates) (II). Of the catalysts tested, 4-piperidinopyridine N-oxide (IIIh) is the best from the viewpoints of catalytic activity and solubility in I. Heating of I in the presence of catalytic amounts (0.02-0.05 molar eq) of IIIh gave II together with the symmetric S,S-dialkyl and S,S-dimethyl dithiocarbonates in good yields. The catalytic behavior of donor-substituted pyridine N-oxides is discussed on the basis of kinetic and molecular orbital calculation data. The complete calculation of the perturbation equation on the initial stage of the reaction was consistent with the experimentally observed activity of the catalysts.
Catalytic rearrangement of O,S-Dialkyl dithiocarbonates to S,S-Dialkyl dithiocarbonates. IV. Use of boron trifluoride etherate as catalyst
Komaki,Kawata,Harano,Taguchi
, p. 3807 - 3814 (2007/10/11)
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