Conjugation amination

Figure 9.62 Sulfo-SMCC can be used to conjugate amine-containing QDs with thiol-containing proteins or other molecules using a two-step coupling procedure.

Enoate 3-substitution and 3-disubstitution cause a decrease in the rate of the initial conjugate addition step of the reaction sequence that is directly related to the steric bulk of the substituent.103,105 Equation (24) provides a representative case in the a-alkylation of enoates by means of conjugate amination-enol-ate alkylation followed by dehydroamination.106 When 3-substitution results in stereoisomeric ( )- and (Z)-alkenoate substrates, tandem difunctionalization typically proceeds with greater facility for ( )-isomers.64103 Obviously, when the double bond of the ester is part of a medium-sized ring, an ( )-alke-noate geometry is mandated in such cases, tandem vicinal difunctionalization proceeds with uniformly excellent results (equation 25).25... 

The above methods were utilized to conjugate a carboxyl group on a hapten to an amino residue on a protein. Obviously, the above reactions could be, and have been, utilized to conjugate an amino residue on a hapten to the carboxyl residues on proteins. However, there are additional methods which have proven useful for conjugating amine containing haptens to proteins. ... 

Aprotic protophillic solvents all nitrogen bases without protons, e.g., pyridine, and other conjugated amines, and fully alkylated amines or amides. The solvents function as Bronsted bases as well as Lewis bases and may have high permittivity. 

Normally, if a low concentration of biogenic amines is ingested, these are quickly detoxified in fhe human body by amine oxidases or through conjugation. Amine... 

Sibi et al. [66] reported the first examples of highly enantioselective conjugate amine additions [67] by use of catalytic amounts of a chiral Lewis acid complex. Addition of 0-benzylhydroxyamine 87 (1.1 equiv.) to the pyrazole-derived crotonamide 86 proceeded smoothly in the presence of stoichiometric amounts of the chiral catalyst prepared from the bis(oxazoline) 50 and MgBr2 OEt2 with high enantiomeric excess (96 % ee) (Sch. 37). This conjugate addition reaction was equally effective with catalytic amounts of the chiral Lewis acid (92 % ee with 30 mol % 88 % ee with 10 mol %). A re face amine addition to the s-cis substrate bound to the chiral complex with tetrahedral- or ds-octahedral arrangements XXXII and XXXni accounts for the product stereochemistry observed (Fig. 7). 

Sibi, M.P. and Itoh, K. (2007) Organocatalysis in conjugate amine additions. Synthesis of P-amino acid derivatives. Journal of the American Chemical Society, 129, 8064—8065. 

Methacrolein and the conjugated amine diaminomaleic dinitrile is stepwise polymerized. The first step is a Schiff-base reaction between the aldehyde groups and the amino groups. In the next step the vinyl groups polymerize resulting a resin [195]. 

Scheme 1 Conjugating amines through squaric acid diester chemistry.

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