Photocatalytic dehydrations for the Ritter reaction

Abstract

Ritter reaction is a powerful method for the synthesis of amides, however, photoinduced Ritter reaction of alcohol is rarely reported. We herein report a simple and additive-free photocatalytic dehydration method...

Advances in the Application of Acetonitrile in Organic Synthesis since 2018

“…The photocatalytic amidation reaction has also been reported. In 2023, Bao et al [77] developed a photocatalytic dehydration of alcohol 102 to synthesize amides 103 (Scheme 24). The reaction uses 2,4,6-triphenylpyrylium tetrafluoroborate (PC1) as a catalyst, and benzyl alcohol and acetonitrile can produce amide after 16 h of blue light irradiation in a nitrogen atmosphere.…”

Visible-light-induced Ritter-type amidation of α-hydroxy ketones in the selective synthesis of α,α-diamido and monoamido ketones

“…4 Simple alcohols are widely utilized as carbocation precursors in the Ritter reaction (Scheme 1b). 5 Recently, there has been an emphasis on developing catalytic Ritter-type C–H amidation for the selective synthesis of amides from alkanes, where the carbocation intermediates are generated by C–H bond oxidation (Scheme 1b). 6 However, these methods encounter certain challenges, including the use of excessive strong acids, transition metal reagents, high temperature, stoichiometric oxidants, and/or unwanted by-products.…”

K2CO3-promoted synthesis of amides from 1-aryl-2,2,2-trifluoroethanones and amines under mild conditions

“…9 The coupling of amines with pre-activated carboxylic acids or carboxylic acid derivatives (esters, aldehydes, acyl halides and acid anhydrides) is an effective method for constructing amide bonds. [10][11][12][13][14][15][16][17][18] In recent years, alcohols, [19][20][21] olens, [22][23][24][25] and alkynes [26][27][28] have also been used as carboxylic acid substitutes to synthesize amides.…”

“…It is worth noting that increasing the temperature does not improve the reaction efficiency, but reducing the temperature from 40 °C to room temperature only provides 20% of the product 3a (Table 1, entry 7-11). Subsequently, various bases including K 2 CO 3 , KHCO 3 , NaHCO 3 , KOAc, NaH 2 PO 4 , NaH, DMAP, and Et 3 N, were screened (Table 1, entries [12][13][14][15][16][17][18][19], and it was found that K 2 CO 3 was the most suitable base with a maximum yield of 93% (Table 1, entry 12). Furthermore, products 3a could not be obtained without the addition of base (Table 1, entry 20).…”