Green Esterification of Carboxylic Acids Promoted by tert‐Butyl Nitrite

In this work, the green esterification of carboxylic acids promoted by tert‐butyl nitrite has been well developed. This transformation is compatible with a broad range of substrates and exhibits excellent functional group tolerance. Various drugs and substituted amino acids are applicable to this reaction under near neutral conditions, with good to excellent yields. TBN‐catalyzed green esterification of carboxylic acids has been developed, which features a broad range of substrates and excellent functional groups tolerance. The mechanistic study confirmed that the nitrous acid formed in situ in the system is the actual catalyst for this transformation.