Synthesis of 1,4-Diketones from Esters Enabled by a Tetraborylethane Reagent.

A modular synthesis method for 1,4-diketones has been developed. Utilizing inexpensive carboxylic acid esters as carbonyl sources and tetraborylethane () as a nucleophilic reagent, a one-pot strategy for constructing two C-C bonds was established. Notably, this reaction proceeds without the involvement of transition metals and exhibits excellent functional group compatibility.

Triflylpyridinium as Coupling Reagent for Rapid Amide and Ester Synthesis.

An effective method has been developed to facilitate the synthesis of amides and esters at ambient temperature within 5 min, in which a stable and easily accessible triflylpyridinium reagent is used. Remarkably, this method not only has a wide range of substrate compatibility but also could realize the scalable synthesis of peptide and ester via a continuous flow process. Moreover, excellent chirality retentions are presented during activation of carboxylic acid.

Triflylpyridinium Enables Rapid and Scalable Controlled Reduction of Carboxylic Acids to Aldehydes using Pinacolborane.

Building up new and efficient methods for the controlled conversion of carboxylic acids to aldehydes is important. Herein, we report a rapid, modular and scalable method for the conversion of carboxylic acids to aldehydes using pinacolborane at ambient temperature, in which a triflylpyridinium reagent is used. The conversion of carboxylic acid to intermediate acylpyridinium by triflylpyridinium is new.

Donor-acceptor fluorophores as efficient energy transfer photocatalysts for [2 + 2] photodimerization.

Mild [2 + 2] photodimerization of enone substrates was induced by donor-acceptor fluorophores. Enone substrates were activated efficiently for anti-head to head dimerizations with a high yield (up to 83%) and high selectivity. The adjustable excited state potential also allows donor-acceptor fluorophores to be used for isomerization of the above substrates, confirming the potential of donor-acceptor fluorophores as energy transfer photocatalysts.