35507-03-0Relevant articles and documents
Broadly Applicable Ytterbium-Catalyzed Esterification, Hydrolysis, and Amidation of Imides
Guissart, Céline,Barros, Andre,Rosa Barata, Luis,Evano, Gwilherm
supporting information, p. 5098 - 5102 (2018/09/13)
An efficient, broadly applicable, operationally simple, and divergent process for the transformation of imides into a range of carboxylic acid derivatives under mild conditions is reported. By simply using catalytic amounts of ytterbium(III) triflate as a Lewis acid promoter in the presence of alcohols, water, amines, or N,O-dimethylhydroxylamine, a broad range of imides is smoothly and readily converted to the corresponding esters, carboxylic acids, amides, and Weinreb amides in good yields. This method notably enables an easy cleavage of oxazolidinone-based auxiliaries.
Selective Monoesterification of Symmetrical Diols Using Resin-Bound Triphenylphosphine
Pathak, Gunindra,Rokhum, Lalthazuala
supporting information, p. 483 - 487 (2015/09/22)
Coupling reactions to make esters and amides are among the most widely used organic transformations. We report efficient procedures for amide bond formation and for the monoesterification of symmetrical diols in excellent yields without any requirement for high dilution or slow addition using resin-bound triarylphosphonium iodide. Easy purification, low moisture sensitivity, and good to excellent yields of the products are the major advantages of this protocol.
The phosphate-carboxylate mixed-anhydride method: A mild, efficient process for ester and amide bond construction
McNulty, James,Vemula, Ramesh,Krishnamoorthy, Venkatesan,Robertson, Al
experimental part, p. 5415 - 5421 (2012/09/08)
A highly efficient carboxylate-phosphate anhydride pathway is described for the direct, economical synthesis of esters and amides from carboxylic acids and alcohols or amines. The reaction proceeds with retention of configuration with both chiral secondary alcohols and α-amino acid derivatives allowing access to useful chiral auxiliaries, ligands, and organocatalysts. Ester and amide products can be isolated directly in high yield due to the water soluble nature of the side products.
Direct formation of esters and amides from carboxylic acids using diethyl chlorophosphate in pyridine
McNulty, James,Krishnamoorthy, Venkatesan,Robertson, Al
scheme or table, p. 6344 - 6347 (2009/04/07)
An efficient method involving pyridine activation of the carboxylate-phosphate anhydride pathway is described resulting in a direct synthesis of esters from carboxylic acids and alcohols, as well as in the formation of useful amide and peptide derivatives. The reaction proceeds with retention of configuration with both chiral secondary alcohols and α-amino acid derivatives. Ester and amide products can be isolated directly in high yield due to the water soluble nature of the side products.
Scope and mechanistic insights into the use of tetradecyl(trihexyl) phosphonium bistriflimide: A remarkably selective ionic liquid solvent for substitution reactions
McNulty, James,Nair, Jerald J.,Cheekoori, Sreedhar,Larichev, Vladimir,Capretta, Alfredo,Robertson
, p. 9314 - 9322 (2007/10/03)
A survey of substitution reactions conducted in a phosphonium bistriflimide ionic liquid is presented. The results demonstrate high selectivity favoring substitution over typically competitive elimination and solvolytic processes even when challenging secondary and tertiary electrophiles are employed. The first reports of Kornblum substitution reactions in an ionic liquid are described that proceed with very high chemoselectivity in favor of nitro over nitroso products and elimi nation side products. The structure-reactivity study indicates that these reactions proceed through a narrow spectrum of pathways ranging from straight SN2 to a preassociation pathway along a saddle point that approaches the SN1 limit. The barrier to the formation of dissociated carbocations is attributed to the structural features of this ionic liquid that favor intervention of the associated nucleophile over dissociation, also preventing cross over to E1 processes. The lack of any basic entity in the phosphonium bistriflimide ionic liquid appears to prevent any potential base-mediated elimination reactions, which makes this a highly selective medium for use in general substitution reactions.
A mild esterification process in phosphonium salt ionic liquid
McNulty, James,Cheekoori, Sreedhar,Nair, Jerald J.,Larichev, Vladimir,Capretta, Alfredo,Robertson, Al J.
, p. 3641 - 3644 (2007/10/03)
A general, high yielding procedure is described for the esterification of carboxylic acids through carboxylate alkylation in phosphonium salt ionic liquid.
Smectogenic Salts Formed by Combination of Alkyl p-Aminobenzoates and p-Ethyl- or p-Chlorobenzenesulfonic Acid
Matsunaga, Y.,Sakamoto S.,Togashi, A.,Tsujimoto, M.
, p. 161 - 166 (2007/10/02)
Two series of smectogenic salts were obtained by combining alkyl p-aminobenzoates with p-ethyl- and p-chlorobenzenesulfonic acids, respectively.The shortest ester alkyl chain required to generate a smectic A phase is nonyl when the former sulfonic acid is employed but the chain may be as short as butyl when the latter is employed.The smectic A-isotropic transition temperature in the second series is significantly higher than that in the first series, indicating that the terminal substituent on the anion is as crucial as that in non-ionic mesogens in determining the mesophase stability. - Keywords: Smectic, alkyl p-aminobenzoates, benzenesulfonates
