Nucleophilic reactions deuteriated

If one limits the consideration to only that limited number of reactions which clearly belong to the category of nucleophilic aromatic substitutions presently under discussion, only a few experimental observations are pertinent. Bunnett and Bernasconi30 and Hart and Bourns40 have studied the deuterium solvent isotope effect and its dependence on hydroxide ion concentration for the reaction of 2,4-dinitrophenyl phenyl ether with piperidine in dioxan-water. In both studies it was found that the solvent isotope effect decreased with increasing concentration of hydroxide ion, and Hart and Bourns were able to estimate that fc 1/ for conversion of intermediate to product was approximately 1.8. Also, Pietra and Vitali41 have reported that in the reaction of piperidine with cyclohexyl 2,4-dinitrophenyl ether in benzene, the reaction becomes 1.5 times slower on substitution of the N-deuteriated amine at the highest amine concentration studied. 

The reaction of silole 44 with KH in THF or DME yields, after work-up with D2O, quantitatively the corresponding deuteriated silole (equation 52) metalated siloles have been suggested as intermediates80. In contrast, the analogous treatment of silole 45 with KH yields a mixture of three NMR spectroscopically characterized potassium compounds (equation 53). The main product of this reaction is the pentavalent silicate 46, which results from the nucleophilic attack of a hydride at the silicon center109. The other two products result from hydride addition to one of the ring carbons. 

The sulphone (97) converts alcohols, ROH, into (98). 7V-Quaternization or protonation of (98) gives a species so susceptible to nucleophilic attack that alkylated derivatives of such poor nucleophiles as CIO4 or FSOs may be prepared. Sulphur dioxide undergoes a reversible ene reaction with alkenes, such as methylenecyclohexene as in (99). In the absence of water, overall allylic shift (to methylcylohexene) merely results, but exhaustive allylic deuteriation of the starting material occurs in the presence of 02 . ... 

Reactions.—, i-Dithianyl Anions. The Corey-Seebach 1,3-dithianyl anion rates as one of the most popular sulphur anions and nucleophilic acylating agents, as demonstrated by its recent use in the syntheses of potential precursors of the macrocyclic antitumour agent maytansine, of cyclopentenones and other unsaturated ketones,of octoses, of lla-hydrox)rprogesterone, of deuteriated aldehydes, of alnusone, of the sex-attractant of the Douglas fir tussock moth, of l,4-diketones, of 3-s-butylglutaraldehyde, of linaloyl... 

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