Lanigan RM, Starkov P, Sheppard TD. Direct synthesis of amides from carboxylic acids and amines using B(OCH2CF3)3.
J Org Chem 2013;
78:4512-23. [PMID:
23586467 PMCID:
PMC3671500 DOI:
10.1021/jo400509n]
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Abstract
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B(OCH2CF3)3, prepared from readily
available B2O3 and 2,2,2-trifluoroethanol, is
as an effective reagent for the direct amidation of a variety of carboxylic
acids with a broad range of amines. In most cases, the amide products
can be purified by a simple filtration procedure using commercially
available resins, with no need for aqueous workup or chromatography.
The amidation of N-protected amino acids with both
primary and secondary amines proceeds effectively, with very low levels
of racemization. B(OCH2CF3)3 can
also be used for the formylation of a range of amines in good to excellent
yield, via transamidation of dimethylformamide.
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