AMIDE

Updated 05-May-2020.

Mondo shtuff from around the internet, all about AMIDE!

A two-step approach to achieve secondary amide transamidation enabled by nickel catalysis: A long-standing challenge in synthetic chemistry is the development of the transamidation reaction. This process, which involves the conversion of one amide to another, is typically plagued by unfavourable kinetic and thermodynamic factors. Although some advances have been made with regard to the transamidation of primary amide substrates, secondary amide transamidation has remained elusive. Here we present a simple two-step approach that allows for the elusive overall transformation to take place using non-precious metal catalysis. The methodology proceeds under exceptionally mild reaction conditions and is tolerant of amino-acid-derived nucleophiles. In addition to overcoming the classic problem of secondary amide transamidation, our studies expand the growing repertoire of new transformations mediated by base metal catalysis.

<img src='https://ui.adsabs.harvard.edu/styles/img/transparent_logo.svg' alt='Direct Synthesis of Amides from Alcohols and Amines with Liberation of H₂”>Direct Synthesis of Amides from Alcohols and Amines with Liberation of H₂: Given the widespread importance of amides in biochemical and chemical systems, an efficient synthesis that avoids wasteful use of stoichiometric coupling reagents or corrosive acidic and basic media is highly desirable. We report a reaction in which primary amines are directly acylated by equimolar amounts of alcohols to produce amides and molecular hydrogen (the only products) in high yields and high turnover numbers. This reaction is catalyzed by a ruthenium complex based on a dearomatized PNN-type ligand [where PNN is 2-(di-tert-butylphosphinomethyl)-6-(diethylaminomethyl)pyridine], and no base or acid promoters are required. Use of primary diamines in the reaction leads to bis-amides, whereas with a mixed primary-secondary amine substrate, chemoselective acylation of the primary amine group takes place. The proposed mechanism involves dehydrogenation of hemiaminal intermediates formed by the reaction of an aldehyde intermediate with the amine.

Borate esters: Simple catalysts for the sustainable synthesis of complex amides

Greener Methods: Catalytic Amide Bond Formation: Sigma-Aldrich is proud to offer a number of products used in catalytic amidation technology.

Amide | Definition of Amide by Lexico: What does amide mean? amide is defined by the lexicographers at Oxford Dictionaries as An organic compound containing the group —C(O)NH₂, related to ammonia by replacing a hydrogen atom by an acyl group.

My botty best at summarizing from Wikipedia: an amide is a compound with the general formula RC(=O)NR′R′′ . R, R′, and R′′ represent organic groups or hydrogen atoms . it can be viewed as a linkages are easily formed, confer structural rigidity, and resist hydrolysis . Amides include many other important biological compounds . low molecular weight amides, such as dimethylformamide, are common solvents . ethanamide and related formal names are rarely encountered . when the amide is derived from a primary or secondary amine, substituents on nitrogen are indicated first in the name . IUPAC recommends e the three bonds of the nitrogen in amides is not pyramidal (as in the amines) but planar . the structure of an amide can be described also as a resonance between two alternative structures . amides don’t have as clearly noticeable acid–base properties in water . withdrawing electrons from the amine by the carbonyl. amides are much stronger bases than carboxylic acids, esters, aldehydes, and ketones . the proton of a primary or secondary amide does not dissociate readily under normal conditions . amides can participate in hydrogen bonding with water and other protic solvents . oxygen atom can accept hydrogen bonds from water . hydrogen bonds also have an important role in the secondary structure of proteins . Typically amides are less soluble than comparable amines and carboxylic acids . they can both donate and accept hydrogen bonds . amide can be distinguished from nitro and cyano groups in IR spec in x-ray crystallography, the C(=O)N center together with the three adjacent atoms characteristically define a plane . amides hydrolyse in hot alkali as well as in strong electrophiles attack the carbonyl oxygen. hydrolysis is catalyzed by both Brnsted acids and Lewis acids . on paper, the simplest method for making amides is by coupling a conventional methods in peptide synthesis use coupling agents such as HATU, HOBt, or PyBOP . amine first deprotonates the carboxylic acid, which reduces its re in recent years there has also been a surge in the development of Boron reagents for amide bond formation . Elimination of water in the hemiaminal to the imine is not observed . transa