Iminoacetic acid

Fig. 3. Bi- and mono-nuclear palladium ions observed by ESI(+)-MS and proposed as catalytic intermediates in the enantioselective Manich-type reaction of enol silyl ethers with N-aryl-iminoacetic acid esters 42. ...

There has been considerable interest from both academics and industry in this reaction since 1980. There are a wide number of uses for the amido acid products surface-active agents and specialty surfactants (Cio-Cie amido acids), intermediates for aspartame sweeteners (phenylalanine), food additives (monosodium glutamate), and chelating agents (iminoacetic acid and polyamido acids). Knifton (Texaco) has done extensive studies of this reaction, as have Ojima and coworkers. ... 

Consider the symmetrical compounds VIII and IX. Substitutive names might be methylenebis(aminoacetic acid) for VIII, and methylenebis(iminoacetic acid) for IX. Additive names might be methylenebis(iminoacetic acid) for VIII, and methylene(bis-nitriloacetic acid) for IX. The additive principle is not carried so far that the names begin with methanebis. The substitutive name for IX is the additive name for VIII, which is a most unpleasant situation. 

Important This assay is not compatible with buffers containing carboxylic add groups, such as sodiiun dtrate or 2i7-(2-acetamido)-iminoacetic acid (ADA), because the Biomol Green complex formation is compromised in such buffers. 

A study was carried out of the formation of In(III) complex with citric acid and some aminopolycarboxylic acids (10,11). In acid neutral media indium forms a 1 1 complex with citric acid as well as with EDTA, di-aminocyclohexanetetraacetic and HMDTA acids, but it forms complexes with the molar ratio of 1 1 and 1 2 with nitrilotriacetic and oxyethyl-iminoacetic acids. 

Based on these preliminary findings, related couplings to pyruvates and iminoacetates were explored as a means of accessing a-hydroxy acids and a-amino acids, respectively. It was found that hydrogenation of 1,3-enynes in the presence of pyruvates using chirally modified cationic rhodium catalysts delivers optically enriched a-hydroxy esters [102]. However, chemical yields were found to improve upon aging of the solvent 1,2-dichloroethane (DCE), which led to the hypothesis that adventitious HC1 may promote re-... 

The N-alkylation of L-cysteine results from a series of reactions involving the condensation of L-cysteine methyl ester (605) with ethyl iminoacetate (606), followed by A-alkylation of the intermediate 4-methoxycarbonyl-2-methylthiazoline (607). Acid hydrolysis of the thiazolinium salt (608 Scheme 301) then gives (609) (70ACS(B)3129). 

Kamochi, Y., Kudo, T. Cyclization of iminoacetals with lanthanide triflates as acid catalyst. Kidorui 1999, 34, 304-305. 

Several methyl 2-cyclopropylacetate derivatives were converted to the corresponding methyl 2-azido-2-cyclopropylacetates by treating the starting material with lithium or potassium hexa-methyldisilazanide, followed by 2,4,6-triisopropylbenzenesulfonyl (trisyl) azide and acetic acid. F or example, formation of 1. It is noteworthy that treatment of the methyl 2-azido-2-cyclopropylacetates with lithium methoxide afforded the corresponding 2-iminoacetates in good yield. " ... 

Esterification, crotonic acid, 149 levulinic acid, 157 thiophene-2-carboxylic acid, 182 o-toluic acid, 162 Ester interchange, 152 Ethanolysis of ethyl iminoacetate, 159 Ether cleavage with HBr, 271... 

Friedel-Crafts alkylations of arenes with mesylates, benzyl or allyl alcohols, aldehyde/diol combinations (reductive alkylation), 1,3-dienes, or alkenes in an ionic liquid are also effectively catalyzed by Sc(OTf)3. Sc(OTf)3 works as an efficient catalyst for the condensation reaction of trimethylhydroquinone with isophytol to afford a-tocopherol. 2-Aminoalkylation of phenols with a-iminoacetates (or glyoxylate/amine) is catalyzed by Sc(OTf)3 to produce amino acid derivatives. The Sc(OTf)3-catalyzed alkylations of indoles with a-hydroxy esters, aziri-dines, acetals, and aldehydes have been utilized as key steps of total syntheses as exemplified in eq 15. ... 

A review of formal aza-Diels-Alder reactions of imines with e-rich dienes and enones, in the presence of Lewis acids/Brpnsted acids/organocatalysts, has been presented. Bifunctional A-acyl aminophosphine catalysts (75) are effective asymmetric organocatalysts in the hetero-4- -2-cycloaddition of a-substituted allenoates with tosylaldimines to produce optically active tetrahydropyridines. The Brpnsted acid-catalysed aza-Diels-Alder reactions of cyclopentadiene with iminoacetates possessing two chiral auxiliaries yielded 2-azabicyclo[2.2.1]hept-5-ene cycloadducts with high exo-selectivities. ... 

Kong, J.-R., Cho, C.-W., Krische, M. J. (2005). Hydrogen-mediated reductive coupling of conjugated alkynes with ethyl (Ai-sulfinyl)iminoacetates Synthesis of unnatural a-amino acids via rhodium-catalyzed C-C bond forming hydrogenation. Journal of the American Chemical Society, 127, 11269-11276. 

In the case of a dianionic species 49, the s)mthesis of racemic a-amino acid 50 by carboxylation may be achieved (eq 63). The lack of enantionselectivity may be due to the presence of a negative charge on the iminoacetal, which decreases the configurational stability of the benzylic organolithium species. In contrast, carboxylation of the monoanionic species 51, formed in the presence of (—)-sparteine, leads to a highly enantioselective result as shown in (eq 64). 

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