Secondary amine functionality

Polymers with primary or secondary amine functionality cannot be prepared directly by RAFT polymerization these groups undergo facile reaction with thiocarbonylthio compounds. Such polymers can be prepared indirectly using RAFT agents with latent amine functionality, such as the phthalimido group in... 

The secondary amine function of dobutamine hydrochloride may be determined by potentiometric titration with perchloric acid using glacial acetic acid as a nonaqueous solvent. Mercuric acetate is used to tie up the chloride ion. 

The Tsogoeva group, in 2006, reported the introduction of newly designed bifunctional secondary amine-functionalized proline-based thioureas (95 and 96) and the primary amine-functionalized thioureas (97-99) for catalysis of the asymmetric addition of ketones to trans-P-nitrostyrenes (Figure 6.30) [260, 261]. Using... 

The complex of Me2Zn with (5, 5 )-ebpe, 107, has been applied successfully as catalyst in the enantioselective reduction of ketones by polymethylhydrosiloxane and combines excellent product yields with high ee values . Its structure comprises the iV,iV-chelate coordination of the ebpe ligand to the MeiZn unit (Figure 51). It is remarkable that in this case the two secondary amine functionalities are coordinated to zinc and leave the Zn—C bonds unaffected. Indeed, usually secondary amines undergo a fast deprotonation reaction with dialkylzinc compounds. 

BMI/amine Michael adduct resins may be further modified and blended with other thermosets or reactive diluents to achieve either specific end-use properties or processability. Epoxy resins are very suitable for the modification of BMI/primary amine adducts, because the secondary amine functionality in the aspartimide structure is a curative for the epoxy group. 

The exo position of the chloropyridine is essential for the antinociceptive potency of epibatidine - its racemic endo diastereoisomer is inactive. Also inactive are amides derived from epibatidine through acylation of the secondary amine function (R = C(O)R ). On the other hand the potency of 7-methylepibatidine (R = Me) is comparable to epibatidine itself, so a basic nitrogen but not necessarily a secondary amine is needed for activity (Li et al., 1993). 

The use of the anion-exchange resin Duolite A-7 for concentrating organic acids was reported as early as 1965 by Abrams and Breslin (7) and more recently by Leenheer (8). A-7 is a high-surface-area, macro-porous, phenol-formaldehyde, weak-base resin. This resin combines weak-base, secondary-amine functional groups with the relatively hydrophilic phenol-formaldehyde matrix to effectively sorb and elute organic acids. 

FTIR spectra of the sample 5 and of the resulting sample 6 (Fig 2) show the disappearance of the characteristic N-H vibration band at 3276 cm assigned to the secondary amine functions upon alkylation step. This result ensures the efficiency of propylene oxide treatment. 

Reduction reactions, which usually convert imine to secondary amine functions, are also metalion specific and usually most successful for the Ni" complexes. Reductions can be by electrochemical means or by chemical reductants such as NaBH4, NiAl/OH, H2/Pt or H2/Ni. H3P02 is specific for conversion of an a-diimine group to a monoimine. Examples of imine complexes which have been reduced to form cyclic amine complexes include (1), (3), (4), (9), (16) and (20). 

The derivatization of the secondary amine functionality of a tropane template is described in more detail in the experimental section. 

Methylation of alkaloids containing either phenolic hydroxy groups or secondary amine functions is the most common procedure for converting such alkaloids to known derivatives many examples are given in Section II,C. Diazomethane is the reagent of choice for O-methylation, and diazoethane for O-ethylation. It is possible to effect O-alkylation in the presence of secondary amine functions, as in the conversion of peinamine to its trideuteriomethyl ether (Section II,C,92) and of A-desmethylthalrugosidine to the O-ethyl ether (Section II,C,29). Another O-alkylation method, exemplified by the preparation of O-methyl, O-ethyl, and O-isopropyl ethers of berbamine (364), consisted of heating the alkaloid in... 

Norcepharanthine (16, R = H, C36H36N206) shows a mass spectral molecular weight 14 a.m.u. less than for cepharanthine. A strong molecular peak at mlz 592 (78%) is flanked by a base peak at m/z 591, a salient feature often encountered with bisbenzylisoquinolines bearing a secondary amine function. The H-NMR spectrum of (+)-2-norcepharanthine is very close to that of (+)-2-cepharanthine, except for... 

Notwithstanding the progress in other reaction types, the main thrust in organo-catalysis research centers is on enantioselective catalysis applications [109,110], of which amine-based asymmetric catalysts form the majority [111]. Most of the reactions proceed via the enamine catalytic cycle (Figure 3.38a) or via imonium intermediates. The most common (and most successful) catalysts for such reactions are proline derivatives. Thanks to its secondary amine functionality and relatively high pKa value, proline (pyrrolidine-2-carboxylic acid) is a good... 

Polyamines through alkylation reaction with chloromethylsilane 1 The secondary amine function of polyaza derivatives are alkylated using chloromethyltrimethyl-silane. 

Moses et al.39 obtained similar results from XPS data of the modification of metal oxides with aminosilanes. From amidization of the immobilized aminosilanes the activity (i.e. free character) of the amino groups was tested. For the bifunctional AEAPTS, all of the primary amine groups are in the active form. Interaction with the surface is restricted to the secondary amine function in the middle of the organic chain. 

L-Proline is perhaps the most well-known organocatalyst. Although the natural L-form is normally used, proline is available in both enantiomeric forms [57], this being somewhat of an asset when compared to enzymatic catalysis [58], Proline is the only natural amino acid to exhibit genuine secondary amine functionality thus, the nitrogen atom has a higher p Ka than other amino acids and so features an enhanced nucleophilicity compared to the other amino acids. Hence, proline is able to act as a nucleophile, in particular with carbonyl compounds or Michael acceptors, to form either an iminium ion or enamine. In these reactions, the carboxylic function of the amino acid acts as a Bronsted acid, rendering the proline a bifunctional catalyst. 

The cyclic secondary amine function at the 4 position of 3,4-dihydro-(2//)-pyridazino[4,5-6][l,4]-oxazin-8(77/)-one derivatives (124) and the primary amino group of 5-amino-3,4-dihydro-(2//)-pyridazino[4,5- ][l, 4]oxazin-8(77/)-one (125) show normal reactivities towards electrophilic attack <81MI 719-01), though their quatemery salts were not formed because of the electron-drawing elfect of the 8-CO group. Reactions of functional groups on the side chain were not influenced by the condensed ring. 

The monoadduct (I) contains a terminal vinyl group and a secondary amine function. Thus, self-condensation appears to be possible. Lithium diisopropylamide was used to create the amide function, instead of butyllithium which could possibly attack the double bond. Thus, the metalation of the secondary amine function is straightforward, and the occurring self-condensation can be monitored by 13C-NMR and by GPC. No side reaction has been detected. This process can be illustrated by the following scheme ... 

Because of the restricted inversion of the asymmetric secondary amine functions, nickel(ll) complexes of Meg[14]-4,1 l-dieneN4 can exist in both the meso and racemic forms, which can be interconverted in solution. The diaster-eoisomers have been distinguished by optical rotation and NMR studies. The NMR spectra show three equally intense resonances (at 2.67, 2.52 and 1.75 ppm for the racemic thiocyanate salt and at 2.69, 2.21, and 1.75 ppm for the meso thiocyanate salt in D2O) assignable to the pairwise equivalent imine methyl groups (equatorial orientation) and to the axial and equatorial geminal methyl groups, respectively. The diastereoisomers each exhibit a single electronic absorption maximum between 21.0 and 23.0 and infrared bands near... 

For example this concept was applied to the synthesis of novel (acyloxyalkoxy) carbonyl bioreversible moieties for primary as well as secondary amines functions in drugs as illustrated with the case of a prodrug from the antibacterial Norfloxacin in scheme 135 (Ref. 194). 

Not a 3,3-sigmatropic but an Swi-like reaction is involved in an oxygen-nitrogen transposition which allows the introduction of a secondary amine function (Scheme 30). °... 

The presence of one methylamino and one dimethylamino group in this alkaloid (CCCLXXIII) is disclosed by its NMR-spectrum which also reveals two tertiary C-methyl groups. On methylation, pachysamine-A furnishes 3a,20 -bisdimethylamino-5a-pregnane Ruschig degradation to 20a-dimethylamino-5a-pregnan-3-one (funtumafrine-C, XXXI) proves the location of the secondary amine function in position 3 225). 

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