Aminals imine synthesis

An overall strategy for the synthesis of 1,2,5-thiadiazoles from the acyclic N-C-C-N grouping and sulfur monochloride was proposed in 1967 (1967JOC2823). The N-C function could vary over oxidation levels of amine, imine, cyanide, oxime and nitroso derivatives. Aliphatic and aromatic compounds having these functionalities in many combinations reacted with sulfur monochloride to form appropriately substituted or fused 1,2,5-thiadiazoles. Based on this model, a large... 

Both electrochemical and chemical oxidative routes are most often utilized for the synthesis of PANI. In an interesting departure from the oxidative route, poly(phenylene amine imine) was prepared via a conventional condensation polymerization, as illustrated in Scheme 63 [302, 303]. Comparison of this structurally well-characterized polymer with oxidatively prepared PANI allowed confirmation of the PANI structure. However, the structure of PANI produced by electrochemical means is less understood. 

Polypropylene imine) dendrimers (see Scheme 1 for structure) have been constructed step by step onto an amine functionalized polystyrene [38, 130, 131]. The challenge in this synthesis is finding conditions for the polypropylene imine) synthesis under which the low MW polystyrene (MW=3200) is soluble [38]. Similar poly(imine) dendrimers with carboxylic acid end groups have also been prepared [130]. The polypropylene imine) dendrimer has also been synthesized on an amino-terminated poly(2-methyl-2-oxazoline) [132]. 

From a.-Amino Acid Amides and Amidines a-Amino acid amides, which fall into the amine-imine class according to the general model (beginning of Section II,B), are converted to 3-alkyl-4-hydroxy-l,2,5-thiadiazoles by reaction with sulfur mono-chloride, thionyl chloride, or thionyl aniline. A large number of -amino acid amides were employed in the synthesis (see Table I)... 

The ability to reduce compounds under acidic conditions is ideal for the reduction of enamines. Protonation of nitrogen gives an iminium salt in acidic media that is then reduced with cyanoborohydride to an amine.Imines can be reduced in acidic media in the presence of many other functional groups, as shown by Cook s reduction of imine 165 to give 166 in 79% yield in a synthesis of substituted tetrahydro-P-carbolines. 2 This reagent is excellent for the reduction of iminium salts at neutral pH as well,l 3 and it is also useful for the reductive alkylation of amines. Dimethylamino derivatives such as 168 can be prepared from the amine (167 in this case) by treatment with formaldehyde and cyanoborohydride, even in the presence... 

Reductive amination. Imines formed in situ from amines and carbonyl compounds are subject to reduction. This method constitutes a convenient synthesis of secondary amines. 

Synthesis of Amines One of the most common strategies for the synthesis of branched amines is the 1,2-addition of a nucleophile to the previously synthesized aldi-mines or ketimines. Avoiding the imine synthesis, though, is highly desirable. MCR-based methodologies toward this end have been developed. 

In 2013, Adimurthy and co-workers reported a TM-free NaOH-catalyzed N-alkylation reaction of 2-aminothiazoles, 2-aminobenzothiazoles, aminopyrimidines, and aminopyridines with benzyhc and heterobenzyhc alcohols under air (Scheme 43) [203]. In condition optimization, the authors found the model reaction of 2-aminobenzothiazole and 4-chlorobenzylalcohol under air afforded a higher yield of the product (93 %) than the one under nitrogen (90 %). Therefore, along with other results of mechanistic studies and the authors own previous work on based-catalyzed imine synthesis from alcohols and amines [204], they proposed that alcohol oxidation to aldehyde by air in the presence of bases is the initiation step of... 

Donthiri RR, Patil RD, Adimurthy S et al (2012) NaOH-catalyzed imine synthesis aerobic oxidative coupling of alcohols and amines. Eur J Org Chem 24 4457- 1460... 

Hydroformylation reactions play a major role in chemical processes to obtain aldehydes from olefins [46]. Aldehyde groups are among the most versatile functional groups in organic synthesis and can be transformed into alcohols, amines, imines, and acids [47]. High temperatures are required for commercial hydroformylation reactions, as these processes proceed at a slower rate than hydrogenation reactions [48]. 

Chiral amine synthesis Transaminases (1° amine), amine dehydrogenases (1° and 2° amine), imine reductases (2° and 3° amine), and monoamine oxidases (cyclic and 1° amine)... 

Additions of Lithiiiin Alkyl Aryl Sulfoxides to AT-PMP Fliioroalkyl/aryl Imines Synthesis of Stereodefined Fliioroalkyl/ai yl Amines, P-Amino Alcohols and Amino Acids. 

Primary and secondary amines also react with epoxides (or in situ produced episulfides )r aziridines)to /J-hydroxyamines (or /J-mercaptoamines or 1,2-diamines). The Michael type iddition of amines to activated C—C double bonds is also a useful synthetic reaction. Rnally unines react readily with. carbonyl compounds to form imines and enamines and with carbo-tylic acid chlorides or esters to give amides which can be reduced to amines with LiAlH (p. Ilf.). All these reactions are often applied in synthesis to produce polycyclic alkaloids with itrogen bridgeheads (J.W. Huffman, 1967) G. Stork, 1963 S.S. Klioze, 1975). 

The nucleophilicity of amine nitrogens is also differentiated by their environments. In 2,4,5,6-tetraaminopyrimidine the most basic 3-amino group can be selectively converted to a Schiff base. It is meta to both pyrimidine nitrogens and does not form a tautomeric imine as do the ortho- and /xira-amino groups. This factor is the basis of the commercial synthesis of triamterene. 

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