One-Pot Synthesis of 2,3-Disubstituted N-Tosylindoles from o-Acyl-N-tosylanilines

Abstract

The reaction of o-acyl-N-tosylanilines with lithium tri­methylsilyldiazomethane followed by treatment with t-BuLi and then electrophiles gave 2,3-disubstituted N-tosylindoles in a one-pot process.

Key words

o-acylanilines - alkylidenecarbene - indoles - lithium trimethylsilyldiazomethane - one-pot synthesis

References

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4

Though the synthesis of 2,3-disubstituted N-tosylindoles from 2 was reported, the method requires three steps and the substituent at the 2-position is limited to acyl, ester or cyano groups.¹⁰

5

When the synthesis of 5a from 2a was carried out by standard step-wise procedure, the overall yield of 5a was ca. 70%.