Triflic Anhydride Promoted Synthesis of Primary Amides and their Conversion into Nitriles

Abstract

A facile, two-pot conversion of carboxylic acids into the corresponding nitriles has been developed using triflic anhydride as a promoter and aqueous NH4OH as a source of nitrogen. The methodology involves synthesis of primary amides from carboxylic acids as the key first step using triflic anhydride and aqueous NH4OH as a source of ­nitrogen. Triflic anhydride is also found to be an excellent reagent for conversion of primary amides into nitriles, affording high yields with considerable chemoselectivity and functional group tolerance. In spite of the mild reaction conditions and broad substrate scope for the two-step conversions, all attempts for one-pot domino conversion of acids into nitriles exhibited limited success because of poor yields.

Neuroprotective Activities of Constituents from Phyllosticta capitalensis, an Endophyte Fungus of Loropetalum chinense var. rubrum

“…The new compound ( 1 ) and twelve known compounds ( 2 – 13 ) ( Figure 1) were isolated from the 95 % ethanol extract of endophytic fungus Phyllosticta capitalensis in rice solid culture by the combination of chromatographic methods, including silica gel column chromatography, MCI gel column chromatography and semipreparative HPLC. The structures of the known compounds ( 2 – 13 ) were identified as xenofuranone B ( 2 ), [17] isoaltenuene ( 3 ), [18] 6,8‐dihydroxy‐5‐methoxy‐3‐methyl‐1 H ‐isochromen‐1‐one ( 4 ), [19] 3‐methyl‐6,8‐dihydroxyisocoumarin ( 5 ), [20] benzeneacetamide ( 6 ), [21] brassicasterol ( 7 ), [22] 5, 6‐epoxyergosterol ( 8 ), [23] citreoanthrasteroid A ( 9 ), [24] demethylincisterol A ( 10 ), [25] chaxine C ( 11 ), [26] linoleic acid ( 12 ) [27] and 2‐hexenoic acid ( 13 ) by comparing their NMR date ( Table S1 – 2 ), Mass Spectrographic (see Supporting Information ) with those reported in the literatures.…”

Tf2O‐Promoted Synthesis of Ureas, Carbamates and Thiocarbamate via Lossen Rearrangement: A Mechanistic Insight

“…Its utility in the synthesis of amides as well as nitriles is recently described by Mahajan and his group. [23] It is also useful in the activation of amides, [24] phosphates and carbamates. [25] One of the interesting approaches for generation of isocyanates involves the use of carbamates, a straight forward approach for the assembly of ureas.…”

“…It is electrophilic in nature. Its utility in the synthesis of amides as well as nitriles is recently described by Mahajan and his group [23] . It is also useful in the activation of amides, [24] phosphates and carbamates [25] .…”