Isothiocyanate, methyl fluoride

The, S n2 reaction between lithium isothiocyanate ion pair and methyl fluoride has been calculated at the MP2(full)/6-31H-G //HF/6-311- -G level of theory in the gas phase and in acetone using the PCM model.108 Both the gas phase and acetone reactions occur with inversion, rather than retention, of configuration. However, the transition states and products are different in the gas phase and in solution methyl thiocyanate is formed in the gas phase by transition state (72) whereas methyl isothiocyanate is formed much more slowly in acetone via the looser transition state (73). 

In a related study, MP2(full)/6-31+G //HF/6-31+G calculations of the 5n reaction between methyl fluoride and the free isothiocyanate ion or the lithium isothiocyanate ion pair108 indicate that the free-ion reaction occurs at the sulfur atom via a normal Sn2 mechanism with inversion of configuration. In the ion-pair reaction, sulfur is again the nucleophilic atom and the reaction occurs with an inversion of configuration but via a six-membered ring transition structure (23). As one might expect, the ion-pair reaction in the gas phase is faster than the free ion gas-phase reaction. 

Cyclohexylcyclohexanone, 180-181 Cyclohexyl fluoride, 627 N-Cyclohexylformamide, 382, 857, 878 Cyclohexylformyl peroxide, 57 Cyclohexylidenecyclohexylamine, 788 C clohexyl iodide, 94, 553, 873 C clohexyl isocyanide, 382, 857, 878 Cyclohexyl isothiocyanate, 181 Cyclohexylmagnesium bromide, 1232 Cyclohexyl methyl ether, 72-73 l-Cyclohexyl-3-(2-morpholinoethyl)-... 

Phenyl isocyanate, 322-323, 402, 427 Phenylisocyanide dichloride, 319 Phenyl isothiocyanate, 323 Phenylketene acetals, 340 Phenyllithium, 95, 96, 343, 386, 415 Phenylmagnesium bromide, 205 Phenylmaleonitrile, 21 Phenylmethanesulfonyl fluoride, 323 2-Phenyl-3-methyl-l,3,2-oxazophospholine, 323... 

The well known fluoride ion-induced liberation of carbanions from silyl compounds has been applied to trimethyl isothiocyanate for generation of the carbanion a- to nitrogen.The method of Hoppe is unsuitable for the direct reaction of methyl isothiocyanate. The carbanion (248) then reacts with carbonyl compounds to form oxazolidines very smoothly at room temperature. 

Scheme 2.104. Fluoride ion induced Peterson reaction of bis(trimethylsilyl) methyl isothiocyanate.

C Fj-NFa), trifluoromethyliminosulphur diiluoride [- - CFj-NFa, (CFa)2NF], pentafluoroethyliminosulphur difluoride CaFs NFa), cyanuric fluoride CFs-NF, (CFa)jNF], thiocyanuric acid [-< CFj-NFj, (CF8)aNF], melamine [- CF3 NF2, (CFs)aNF, CFa(NFa)a], methyl thiocyanate (-> CFa NFj), and methyl isothiocyanate CFs-NFa) carbon tetra-fluoride and nitrogen trifluoride were the major products from these fluorina-tions, and a study has been made of the production of the latter via electrochemical fluorination of urea and related compounds. Details of the production of AtALdifiuorotrifluoromethylamine via injection of carbon tetrafluoride into a nitrogen plasma at 1500—6000 K and direct fluorination of potassium cyanide" have appeared in the patent literature preparation of this difluoroamine by u.v. irradiation of a mbcture of hexafluoro-acetone and tetrafluorohydrazine has also been described, and the new compounds CFCla-NFa, CClj-NFg, and ClS-CCIj-NF, have been obtained by photolysis of the hydrazine in the presence of thiocarbonyl chloride. ... 

O-acetyl-jS-D-glycopyranosides from 0-, m- and p-02T C H 0 a-nitro esters from methyl nitroacetate, and alkyl phenyl selenides from PhSe". Similarly arenesulfonyl fluorides or isothiocyanates can be produced from arenesulfonyl chlorides and F" or SCN", and arene-carboxylic acid cyanides and isothiocyanates from arenecarboxylic acid chlorides and CN" or SCN ... 

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