3389-56-8Relevant academic research and scientific papers
Remote, Late-Stage Oxidation of Aliphatic C-H Bonds in Amide-Containing Molecules
Nanjo, Takeshi,De Lucca, Emilio C.,White, M. Christina
, p. 14586 - 14591 (2017)
Amide-containing molecules are ubiquitous in natural products, pharmaceuticals, and materials science. Due to their intermediate electron-richness, they are not amenable to any of the previously developed N-protection strategies known to enable remote aliphatic C-H oxidations. Using information gleaned from a systematic study of the main features that makes remote oxidations of amides in peptide settings possible, we developed an imidate salt protecting strategy that employs methyl trifluoromethanesulfonate as a reversible alkylating agent. The imidate salt strategy enables, for the first time, remote, nondirected, site-selective C(sp3)-H oxidation with Fe(PDP) and Fe(CF3PDP) catalysis in the presence of a broad scope of tertiary amides, anilide, 2-pyridone, and carbamate functionality. Secondary and primary amides can be masked as N-Ns amides to undergo remote oxidation. This novel imidate strategy facilitates late-stage oxidations in a broader scope of medicinally important molecules and may find use in other C-H oxidations and metal-mediated reactions that do not tolerate amide functionality.
Manganese-Catalyzed Direct Conversion of Ester to Amide with Liberation of H2
Mondal, Akash,Subaramanian, Murugan,Nandakumar, Avanashiappan,Balaraman, Ekambaram
supporting information, p. 3381 - 3384 (2018/06/11)
A simple and efficient Mn-catalyzed acylation of amines is achieved using both acyl and alkoxy functions of unactivated esters with the liberation of molecular hydrogen as a sole byproduct. The present protocol provides an atom-economical and sustainable route for the synthesis of amides from esters by employing an earth-abundant manganese salt and inexpensive phosphine-free tridentate ligand.
Direct Synthesis of Amides by Dehydrogenative Coupling of Amines with either Alcohols or Esters: Manganese Pincer Complex as Catalyst
Kumar, Amit,Espinosa-Jalapa, Noel Angel,Leitus, Gregory,Diskin-Posner, Yael,Avram, Liat,Milstein, David
, p. 14992 - 14996 (2017/10/25)
The first example of base-metal-catalysed synthesis of amides from the coupling of primary amines with either alcohols or esters is reported. The reactions are catalysed by a new manganese pincer complex and generate hydrogen gas as the sole byproduct, thus making the overall process atom-economical and sustainable.
Amides in one pot from Carboxylic Acids and Amines via Sulfinylamides
Bai, Jianfei,Zambron, Bartosz K.,Vogel, Pierre
supporting information, p. 604 - 607 (2014/04/03)
An efficient method has been developed for the direct amidification of carboxylic acids via sulfinylamides preformed in situ by the reaction of pure amines with prop-2- ene-1-sulfinyl chloride. The method can be applied to aliphatic acids, including pivalic acid, aromatic acids, and primary and secondary amines. It is compatible with acids bearing unprotected alcohol, phenol, and ketone moieties and applicable to the synthesis of peptides. It does not induce their a-epimerization.
Amide formation in one pot from carboxylic acids and amines via carboxyl and sulfinyl mixed anhydrides
Zambron, Bartosz K.,Dubbaka, Srinivas R.,Markovic, Dean,Moreno-Clavijo, Elena,Vogel, Pierre
supporting information, p. 2550 - 2553 (2013/07/05)
An efficient method has been developed for the preparation of yet unknown acyclic mixed anhydrides of carboxylic and sulfinic acids. Sterically hindered 2-methylbut-3-ene-2-sulfinyl carboxylates add primary and secondary amines preferentially onto the carbonyl moieties realizing a new method for the one-pot preparation of carboxamides. It uses 1:1 mixtures of carboxylic acids and amines without a base, requires no excess of reagents, and liberates only volatile coproducts. Protected di- and tripeptides have been prepared in solution without epimerization by application of this method.
Synthesis of amides from esters and amines with liberation of H2 under neutral conditions
Gnanaprakasam, Boopathy,Milstein, David
supporting information; experimental part, p. 1682 - 1685 (2011/04/22)
Efficient synthesis of amides directly from esters and amines is achieved under mild, neutral conditions with the liberation of molecular hydrogen. Both primary and secondary amines can be utilized. This unprecedented, general, environmentally benign reaction is homogeneously catalyzed under neutral conditions by a dearomatized ruthenium-pincer PNN complex and proceeds in toluene under an inert atmosphere with a high turnover number (up to 1000). PNP analogues do not catalyze this transformation, underlining the crucial importance of the amine arm of the pincer ligand. A mechanism is proposed involving metal-ligand cooperation via aromatization-dearomatization of the pyridine moiety and hemilability of the amine arm.
A new efficient synthesis of α-methyl-β-ketoesters through an Eschenmoser sulfide reaction
Bellec, Christian,Gaurat, Olivier
, p. 1289 - 1293 (2007/10/03)
Various α-methyl-β-ketoesters were readily synthesized through Eschenmoser condensation of thioamides with a commercially available bromoester. β-Enaminoesters were easily prepared through this sulfide contraction reaction and were hydrolysed to afford the corresponding β-ketoesters in moderate to good yields.
