Reactions of t-Boc-Protected Amines with Difluorocarbene

Abstract

The reactions of t-Boc-protected secondary and primary amines with difluorocarbene generated from trimethylsilyl (fluorosulfonyl)difluoroacetate [Me₃SiOC(O)CF₂SO₂F] (TFDA) in toluene at 110 °C results in the replacement of t-Bu by difluoromethyl in the t-Boc group. This reaction can be carried out in the presence of CH₂Br and COOMe moieties in the structure of the protected amine. In the example of a t-Boc-protected amine containing a C=C double bond, replacement of the t-Bu group and/or cyclodifluoropropanation takes place. Difluoromethyl esters are shown to react with primary and secondary amines yielding the corresponding ureas.

Key words

t-Boc group - trimethylsilyl (fluorosulfonyl)difluoroacetate - t-Bu/CHF₂ replacement - difluoromethylcarbamate - acylation - urea

• References

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