Amines cyano

Dehydrocyanation of cyano amines 9-2 Dehydrogenation of tertiary amines... 

Nitrile-stabilized anions, generated for example by lithiation of benzyl cyanide and propionitrile, have been added diastereoselectively to aromatic aldimines.50 Acid workup gives /5-cyano amines. Alternatively, addition of RX gives /3-R-substituted-/3-cyanoamines. The factors determining des in both reaction versions have been investigated. 

The principle can be also applied to the addition of nitriles to imines. The reaction of 2-methylmalononitrile (16) with 4-methoxycarbonyl-N-(4-methylbenzylide-ne)aniline(17) in the presence of 1 [8] or RhH(CO)(PPh3)3 (15) [16] gave the corresponding cyano amine 18 in 91 % yield. 

An important application of oxidation of a C-H bond adjacent to a nitrogen atom is the selective oxidation of amides. This reaction proceeds in the presence of ferf-BuOOH as the oxidant and Ru(II) salts. Thus in the example of Eq. (36), the a-tert-butylperoxy amide of the isoquinoline was obtained, which is an important synthetic intermediate for natural products [138]. This product can be conveniently reacted with a nucleophile in the presence of a Lewis add. Direct trapping of the iminium ion complex by a nudeophile was achieved in the presence of trimethylsilyl cyanide, giving a-cyanated amines as shown in Eq. (37) [45]. This ruthenium/peracid oxidation reaction provides an alternative to the Strecker reaction for the synthesis of a-amino acid derivatives since they involve the same a-cyano amine intermediates. In this way N-methyl-N-(p-methoxyphenyl) glycine could be prepared from N,N-dimethyl-p-methoxyaniline in 82% yield. 

In a study of the Hofmann-Loffler reaction, the jV-chloro-amine (8a) was irradiated in trifluoroacetic acid solution and underwent photolysis to yield the pyrrolidine (9a) together with the 205-isomer (9b) in a ratio 8 1. The starting amine (8b) was prepared by hydrogenation of (8c), followed by von Braun demethylation and hydrolysis of the JV-cyano-amine (8d) which was so formed. The n.m.r. spectrum of (8b) and of related amines in the presence of lanthanide shift reagents was discussed.10... 

The first important MCR was developed by Strecker in 1850 (Scheme 1) [20]. In this reaction ammonia, an aldehyde and hydrogen cyanide combine to form a-cyano amines 1, which upon hydrolysis form a-amino acids 2. Also, heterocyclic compounds were obtained using MCRs. An example of this is the Hantzsch reaction, discovered in 1882 [21]. This reaction is a condensation of an aldehyde with two equivalents of a (3-ketoester in the presence of ammonia resulting in the formation of dihydropyridines 3. A comparable reaction is the Biginelli reaction, founded in 1893 ([22] and see for review [23]). This reaction is a 3-component reaction (3CR) between an aldehyde, a (3-ketoester and urea to afford dihydropyrimidines 4. 

Displacement of a cyano group in a-cyanoketones is possible. Treatment of the a-cyanoketone with Sml2 followed by addition of an excess of allyl bromide gave the a-allyl ketone derivative. a-Cyano amines react with allyl bromide and then zinc metal to give homoallylic amines after treatment with dilute acetic acid in... 

HCN adds to imines, Schiff bases, hydrazones, oximes, and similar compounds. Cyanide can be added to iminium ions to give a-cyano amines (83). 

In the presence of a chiral zirconium " " or aluminum " catalyst, Bu3SnCN react with imines to give a-cyanoamines enantioselectively. The reaction of an imine and TMSCN gives the cyano amine with good enantioselectivity using a chiral scandium catalyst.Titanium catalysts have been used in the presence of a chiral Schiff base. Treatment of an imine with a chiral 1,4,6- triazabicy-clo[3.3.0]oct-4-ene and then HCN give the a-cyano amine with good enantioselectivity. 

Pyridine-substituted nicotines, nornicotines, and anabasines are available from a-cyano-amines by a new synthesis. The syntheses of ( )-[l - N]nornicotine and ( )-[l - N]nicotine have been described, from cyclopropyl 3-pyridyl ketone and [ N]formamide. 4-Methylnicotine has been prepared it shows no nicotine-like pharmacological activity. " An investigation into the stereochemical factors involved in the behaviour of nicotine and related compounds in the Menschutkin reaction has been conducted.A bridged nicotine , 1,2,3,5,6,10b-hexahydropyrido[2,3-g]indolizine (44), has been synthesized by carboxylation of the dilithium derivative of 2-methylnornicotine followed by cyclisation and reduction with borane in tetrahydrofuran. Several 5-halogeno-nicotines have been prepared and their pK values and biological activities measured. ... 

Alternative Names/Abbreviations Carbodiimide, cyano-amine, hydrogen cyanamide, cyanogen nitride... 

In order for the separation to take place, a more polar solvent (than the original sample matrix) will be used to effect the desorption of the analyte molecules from the packing material. Examples of packing material include silica bonded with cyano, amine, and diol groups, as with the stationary phase of columns in normal phase chromatography (see Chapter 4 for further explanation). 

Normal phase chromatography systems use a polar stationary phase with a nonpolar mobile phase. Generally, the packing materials within the normal phase columns are composed of unmodified silica spherical beads (cyano, amine, or diol packing materials can also be used) with the mobile phase consisting of nonpolar organic solvents such as ethanol, chloroform, propanol, or hexane. Table 4.3 outlines the main differences between typical normal phase packing materials. 

Anodic cyanation of tertiary aliphatic and heterocyclic amines in sodium cyanide-aqueous methanol solutions using platinum electrodes takes place a-to the nitrogen atom to form the a-cyano-amines in reasonable yields. ... 

Sequence of events (1) imine formation (2) trap with cyanide (3) amine aikyiation, a-Cyano amine formation reversibie ... 

Synthesis via Iminium Ions. a-Cyano amines react with AgBp4 with the formation of an intermediate iminium ion. This has been used synthetically as a method for removal of the cyano group either by a consecutive reduction to the amine (eq 9) or by elimination to the imine or enamine. ... 

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