Direct Conversion of N-Methoxy-N-methylamides (Weinreb Amides) to Ketones via a Nonclassical Wittig Reaction

Abstract

[reaction: see text] N-Methoxy-N-methylamides (Weinreb amides) are converted efficiently into ketones by reaction with alkylidenetriphenylphosphoranes and in situ hydrolysis of the product.

Introducing Glycerol as a Sustainable Solvent to Organolithium Chemistry: Ultrafast Chemoselective Addition of Aryllithium Reagents to Nitriles under Air and at Ambient Temperature

“…The identity of obtained ketones 3a, [24] 3b, [25] 3c, [24] 3d, [24] 3e, [24] 3f, [24] 3g, [24] 3h, [24] 3j, [26] 3k, [27] 3l [24] and 3m [28] was assessed by comparison of their 1 Ha nd 13 CNMR spectroscopic data with those reported in the literature. In ag lass tube, the appropriate nitrile (0.5 mmol) was added to the corresponding alternative solvent (0.5 g) under air,f ollowed by the addition of PhLi (1 mmol) at room temperature, and the reaction mixture was stirred for 2-3 s. The reaction was then stopped by addition of as aturated solution of the Rochelle salt (sodium potassium tartrate tetrahydrate).…”

Water Solvent Method for Esterification and Amide Formation between Acid Chlorides and Alcohols Promoted by Combined Catalytic Amines: Synergy between N‐Methylimidazole and N,N,N′,N′‐Tetramethylethylenediamine (TMEDA)

“…The following esters and amides obtained in this paper are known compounds: 1-octyl 3-phenylpropanoate, [9] 9-decen-1-yl 3-phenylpropanoate, [10] 6-chlorohexyl 3-phenylpropanoate, [10] 2-hexyn-1-yl 3-phenylpropanoate, [10] ethyl 6-(3-phenylpropanoyloxy)hexanoate, [10] phenyl 3-phenylpropanoate, [11] 1-phenylethyl 3-phenylpropanoate, [12] methallyl 3-phenylpropanoate, [13] 1-octyl cyclohexanecarboxylate, [14] 1-octyl 3,3-dimethylbutanoate, [15] 1-octyl benzoate, [10] 3-octyl benzoate, [16] 1-octyl methacrylate, [17] 1-ethynyl-2-methyl-2-pentenyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate (chlovaporthrin: a vaporthrin analogue), [18] 3-phenoxybenyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate (permethrin), [19] N-carbobenzoxy-l-proline phenylmethyl ester, [20] N-methyl-N-phenyl-3-phenylpropanamide, [21] N-phenyl-3-phenylpropanamide, [22] N-(4-chlorophenyl)-3-phenylpropanamide, [23] N-(2-chlorophenyl)-3-phenylpropanamide, [23] N-[(S)-1-phenylethyl]-3-phenylpropanamide, [10] N-(3-phenylpropionoyl)piperidine, [10] N-methoxy-N-methyl 3-phenylpropanamide, [24] N-(2,2-dimethoxyethyl)-3-phenylpropanamide, [25] N-methyl-N-phenylbenzamide, [26] N-phenylbenzamide, [27] N-benzoylpiperidine, [10] N-methyl-Nphenylcyclohexanamide, [28] N-phenylcyclohexanamide, [29] Ncyclohexanecarbonylpiperidine, [10] N-methyl-N-phenyl-3,3-dimethylbutanamide, [30] N-phenyl-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanamide. [31] Typical Procedure for Esterification (Table 2, entry 1).…”

Efficient synthesis of N-protected amino/peptide Weinreb amides from T3P and DBU

“…7,8 Recently Weinreb amides have been utilized in the synthesis of trifluoromethylketones. 9 A specific class is the N-protected amino/peptide Weinreb amides, which are the key constituents for the preparation of unnatural amino acids and peptidomimetics.…”