Oxidative Synthesis Of Amides Research Articles

Reagent-free aerobic oxidative synthesis of amides from aldehydes and isothiocyanates

A reagent-free autoxidative reaction of aldehydes with isothiocyanates is developed to readily access amides, involving capture of carboxylic acids in situ generated from aldehydes by isothiocyanates as both coupling mediators and amine surrogates.

ChemInform Abstract: Polyethylene Glycol as a Recyclable Reaction Medium for Gold‐Catalyzed Direct Oxidative Amide Synthesis from Aldehydes and Amines.

AbstractThe catalyst as well as the solvent can be easily recovered and reused without significant loss of activity.

Polyethylene Glycol as a Recyclable Reaction Medium for Gold-Catalysed Direct Oxidative Amide Synthesis from Aldehydes and Amines

Polyethylene glycol (PEG) was used as the recyclable reaction medium for gold-catalysed oxidative amidation of aldehydes with amines by using tert-butyl hydroperoxide (TBHP, 70% aqueous) as the oxidant. The reaction proceeded efficiently to provide the corresponding products in moderate to good yields under mild conditions. Both the catalysts and solvent can be easily recovered and reused by simple extraction without significant loss of activity.

Iron-Catalyzed Cα-H Oxidation of Tertiary, Aliphatic Amines to Amides under Mild Conditions.

De novo syntheses of amides often generate stoichiometric amounts of waste. Thus, recent progress in the field has focused on precious metal catalyzed, oxidative protocols to generate such functionalities. However, simple tertiary alkyl amines cannot be used as starting materials in these protocols. The research described herein enables the oxidative synthesis of amides from simple, noncyclic tertiary alkyl amines under synthetically useful, mild conditions through a biologically inspired approach: Fe-catalyzed Cα-H functionalization. Mechanistic investigations provide insight into reaction intermediates and allow the development of a mild Cα-H cyanation method using the same catalyst system. The protocol was further applied to oxidize the drug Lidocaine, demonstrating the potential utility of the developed chemistry for metabolite synthesis.

Iron‐Catalyzed CαH Oxidation of Tertiary, Aliphatic Amines to Amides under Mild Conditions

AbstractDe novo syntheses of amides often generate stoichiometric amounts of waste. Thus, recent progress in the field has focused on precious metal catalyzed, oxidative protocols to generate such functionalities. However, simple tertiary alkyl amines cannot be used as starting materials in these protocols. The research described herein enables the oxidative synthesis of amides from simple, noncyclic tertiary alkyl amines under synthetically useful, mild conditions through a biologically inspired approach: Fe‐catalyzed CαH functionalization. Mechanistic investigations provide insight into reaction intermediates and allow the development of a mild CαH cyanation method using the same catalyst system. The protocol was further applied to oxidize the drug Lidocaine, demonstrating the potential utility of the developed chemistry for metabolite synthesis.

Size of Gold Nanoparticles Driving Selective Amide Synthesis through Aerobic Condensation of Aldehydes and Amines

AbstractMetal nanoparticles (NPs) have attracted much attention in many fields due to their intrinsic characteristics. It is generally accepted that smaller NPs (1.5–3 nm) are more active than larger NPs, and reverse cases are very rare. We report here the direct aerobic oxidative amide synthesis from aldehydes and amines catalyzed by polymer‐incarcerated gold (Au) NPs. A unique correlation between imine/amide selectivity and size of NPs was discovered; Au‐NPs of medium size (4.5–11 nm) were found to be optimal. High yields were obtained with a broad range of substrates, including primary amines. Au‐NPs of medium size could be recovered and reused several times without loss of activity, and they showed good activity and selectivity in amide formation from alcohols and amines.

Size of Gold Nanoparticles Driving Selective Amide Synthesis through Aerobic Condensation of Aldehydes and Amines

Metal nanoparticles (NPs) have attracted much attention in many fields due to their intrinsic characteristics. It is generally accepted that smaller NPs (1.5-3 nm) are more active than larger NPs, and reverse cases are very rare. We report here the direct aerobic oxidative amide synthesis from aldehydes and amines catalyzed by polymer-incarcerated gold (Au) NPs. A unique correlation between imine/amide selectivity and size of NPs was discovered; Au-NPs of medium size (4.5-11 nm) were found to be optimal. High yields were obtained with a broad range of substrates, including primary amines. Au-NPs of medium size could be recovered and reused several times without loss of activity, and they showed good activity and selectivity in amide formation from alcohols and amines.

A novel oxidative procedure for the synthesis of benzamides from styrenes and amines under metal-free conditions

An interesting procedure for the oxidative synthesis of amides from styrenes and amines has been developed. Various primary amides were formed in moderate yields (25-81%). Secondary amides can be produced in moderate yields as well (41-68%). Notably, no transition metal catalyst was needed for this transformation. This is the first example of oxidative transformation of styrenes to benzamides.

ChemInform Abstract: Direct Use of Dioxygen as an Oxygen Source: Catalytic Oxidative Synthesis of Amides.

AbstractA transition‐metal‐catalyzed direct oxidative synthesis of amides from alkynes and amines under mild conditions is presented.

Direct use of dioxygen as an oxygen source: catalytic oxidative synthesis of amides

The first transition-metal-catalyzed direct oxidative synthesis of amides by using dioxygen as an oxygen source has been developed under mild conditions, in which DBU was used as the key additive. The present methodology, which utilizes dioxygen as an oxidant and oxygen source and cheap copper salts as catalysts, opens up an interesting and attractive avenue for the synthesis of amide functionality.

Oxidative Synthesis of Amides and Pyrroles via Dehydrogenative Alcohol Oxidation by Ruthenium Diphosphine Diamine Complexes

A series of ruthenium complexes can perform the acceptorless dehydrogenation of diols as well as the reaction of amines and alcohols to form ester, lactam, and amide products. The ligand criteria necessary for high catalytic activity are identified to guide future catalyst development for amide formation from amines and alcohols. These complexes can be employed in a dehydrogenative Paal–Knorr pyrrole synthesis to give 2,5-dimethyl-N-alkylpyrroles.

ChemInform Abstract: Oxidative Amide Synthesis Directly from Alcohols with Amines

AbstractReview: 37 refs.

Oxidative amide synthesis directly from alcohols with amines

Transition metal catalyzed oxidative amide synthesis directly from primary alcohols and amines is a highly atom economical transformation that evolves hydrogen gas as the only by-product. Several Ru-, Rh-based homogeneous and Ag-based heterogeneous catalysts have been developed for direct amide synthesis. Most of the developed catalysts showed excellent activity with sterically unhindered alcohols and amines; however, limited activity was observed with sterically hindered alcohols or amines, less basic aryl amines, and secondary amines. This account provides an overview of recent advances and challenges in direct amide synthesis.

Oxidative Amide Synthesis and N‐Terminal α‐Amino Group Ligation of Peptides in Aqueous Medium.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Oxidative Amide Synthesis and N-Terminal α-Amino Group Ligation of Peptides in Aqueous Medium

A new method for oxidative synthesis of amides from alkynes and amines in high yields (up to 96%) using [Mn(2,6-Cl2TPP)Cl] 1 as a catalyst and Oxone/H2O2 as an oxidant in aqueous medium has been developed. This method could be used for N-terminal alpha-amino group ligation of unprotected peptides with aryl, aliphatic, and internal alkynes under mild conditions.