Thiols alkylations, sodium hydride

Reaction of Resin-Bound Iron Complex (54) with Alkyl Mercaptans, Thiophenols, and Phenols (Fig. 9)31. Sodium thiolates are prepared analogously to the alkoxides from thiol and sodium hydride, except that dry DMF is used as a solvent. The substitution on the polymer-bound arene (54) is performed at 70° in DMF within 16 h. The resin is filtered and washed with DMF (2 x 50 ml), MeOH (2 x 50 ml), H20 (2 x 50 ml), MeOH (2 x 50 ml), and CH2CI2 (3 x 50 ml) and then dried in vacuo at 40° to yield a red resin. 

Selenium/Sulfur Acids. A strong base such as sodium hydride is not normally needed to facilitate alkylation of thiols. However, it was necessary to use sodium hydride for the alkylation of 5-bromo-i>-pentano-1,4-lactones (eq 45). The base typically employed for this transformation (NaOMe) is not compatihle with the lactone functionality. 

Therefore, it is not necessary to prepare the thiolate in a separate reaction with a sttong base, as is required in the reaction of alcohols with sodium hydride. Sulfides are usually prepared by adding the alkyl halide to a basic alcoholic solution of the thiol. 

Tributyltin hydride, 316 Zinc iodide, 280 From alkyl halides Lithium aluminum hydride-Ceri-um(III) chloride, 159 Palladium catalysts, 230 Sodium cyanoborohydride-Tin(II) chloride, 280 From alkyl sulfonates Lithium triethylborohydride, 153 From thiols... 

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