Sulfonylmethyl isocyanides

Fig. 5 Selected examples for the formation of heterocycles starting from either isocyano amides (2) or sulfonylmethyl isocyanides (3)...

Toluene-p-sulfonylmethyl isocyanide (32) ( Tosmic ) reacts in a base-induced cycloaddition (in protic medium) with aldimines. Toluene-p-sulfinic acid is eliminated to yield 1,5-disubstituted imidazoles (33 = H) in... 

TosMIC can be efriciently alkylated with primary alkyl halides, isopropyl iodide and benzyl bromide both to the corresponding mono- or di-alkyl derivatives using NaH in DMSO or 40% aq. NaOH in and in the presence of Bu"4NI (Scheme 125). The resulting compounds have then been transformed to aldehydes and ketones, including cycloalkanones, and the method has been successfully applied to the synthesis of optically active 2-methylcyclobutanone from the chiral sulfonylmethyl isocyanide and 1,3-dibromobutane. ... 

The above synthesis gives an example of the high synthetic value of 1-substituted TosMICs (p-toluenesulfonyl methylisocyanides). TosMIC 1600 has been created by van Leusen, who describes syntheses of some chiral sulfonylmethyl isocyanides as TosMIC analogues [1201]. Most of the isocyanides 1600-1605 are prepared by dehydration of the corresponding formamides with phosphoryl chloride, whereby yields of 60-85% are obtained. The chiral isocyanides are compared in terms of their ability to achieve asymmetric induction in base-mediated reactions with... 

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