A scalable protocol of direct N-mono/dialkyl/fluoroalkylation of primary/secondary amines has been constructed with various carboxylic acids as coupling agents under the catalysis of a simple air-tolerant inorganic salt, K 3 PO 4. Advantageous features include 100 examples, 10 drugs and druglike amines, fluorinated complex tertiary amines, gram-scale synthesis and isotope-labelling amine, thus demonstrating the potential applicability in industry of this methodology. The involvement of relatively less reactive silicon-hydride compared with the traditional reactive metal-hydride or boronhydride species required to reduce the amide intermediates presumably contributes to the remarkable functional group compatibility.
Direct
thioesterification of carboxylic acids with thiols using
nontoxic activation agents is highly desirable. Herein, an efficient
and practical protocol using safe and inexpensive industrial waste
polymethylhydrosiloxane as the activation agent and K3PO4 with 18-crown-6 as a catalyst is described. Various functional
groups on carboxylic acid and thiol substituents can be tolerated
by the present system to afford thioesters in yields of 19–100%.
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