Tertiary amines interaction

Increased substitution on the nitrogen tertiary amines interact more strongly than secondary amines, which interact more strongly than primary amines, presumably because of the electron donating ability of alkyl groups... 

We have investigated the IR spectra of DBTDL, triethylamine and the 1/1 combination of these compounds respectively (Fig.l). When IR-1 and IR-3 are compared significant modifications in the region of 1700 and 1650 to 1560 cm l are noted and are consistent with metal-tertiary amine interactions probably the breaking of the bridge bond between carboxylate and metal and coordination of the amine to the metal via the nitrogen. Entelis reported similar observations (27) but disregards them when he proposes the structures II and III. 

The following preparation of triethyl phosphite illustrates the interaction of phosphorus trichloride and ethanol in the presence of dimethylaniline the preparation of di-isopropyl hydrogen phosphite illustrates that of phosphorus trichloride and isopropanol in the absence of a tertiary amine. 

The in-out bicyclic amines prepared by Simmons and Park bear a remarkable semblance to the cryptands but lack the binding sites in the bridges. As a result, these molecules interact with electrophiles in a fashion similar to other tertiary amines and generally do not exhibit strong interactions with alkali or alkaline earth metal ions. The in-out bicyclic amines are prepared by reaction of the appropriate acid chlorides and amines in two stages to yield the macrobicyclic amine after reduction of the amidic linkages. A typical amine is shown above as compound 18. 

Tin enolates are also used in aldol reactions.27 Both the Sn(II) and Sn(IV) oxidation states are reactive. Tin(II) enolates can be generated from ketones and Sn(II)(03SCF3)2 in the presence of tertiary amines.28 The subsequent aldol addition is syn selective and independent of enolate configuration.29 This preference arises from avoidance of gauche interaction of the aldehyde group and the enolate P-substituent. The syn stereoselectivity indicates that reaction occurs through an open TS. 

Using l,3-bis[bis(2-pyridylmethyl)amino]benzene, Schindler et al. investigated the structures and properties of complexes (738) linear (weak interaction with the tertiary amine)/distorted... 

Products derived from intermediate zwitter-ions have been obtained in the reactions of benzynes with tertiary amines 1>. Benzyne generated by the reaction of -butyl-lithium with fluorobenzene interacts with AT.Af-dimethylaniline to yield iV-methyl diphenylamine and AT-ethyl diphenylamine 132,133). Using the reaction of chlorobenzene with n-butyl-lithium to generate benzyne resulted in the formation of increased amounts of 2-A7,AT-dimethylaminobiphenyl 132,133)... 

Herbette et al. compared the sorption site of the structurally similar tertiary amines propranolol and timolol [164]. Propranolol has a naphthalene substituent on the aliphatic chain, which is deeply incorporated into the hydrophobic core of the membrane. In contrast, timolol carries a partially charged morphine ring at the same place. This substituent, due to its polarity and partial charge, does not interact favourably with the membrane interior. Consequently, the AnW at pH 7.5 is 20 times higher for propranolol than for timolol, and timolol has less influence on the phase transition. 

N-Dealkylation reactions are not restricted to tertiary amines. Secondary amines as well as primary amines can also be dealkylated although both types are less favored than tertiary amines. In the case of primary amines, the lone pair of electrons of the amino group can interact and complex with the Fe3+ of heme. Thus primary amines tend to be inhibitors of P450 activation and for that reason are generally poor substrates. Secondary amines have metabolic properties intermediary between those of tertiary amines and primary amines. They are less-effective inhibitors because of increased steric hindrance to complex formation but are also better substrates because they are less-effective inhibitors and thereby increase the effective concentration of enzyme. 

The calculated radii with all interactions included are somewhat smaller than the radii measured with SANS, whereas the radii obtained with only the van der Waals repulsions taken into account are somewhat larger. As could be anticipated, the sizes of the dendrimers are dependent on the pH of the solution. Since both the primary and the tertiary amine groups may be protonated, repulsions begin when the pH of the solution is decreased. 

More /V-acylurea is generated if tertiary amine is present because the latter removes any protons that might prevent the rearrangement (see Section 2.12). The two intramolecular reactions also occur to a greater extent when interaction between the O-acylisourea and the /V-nucleophile is impeded by the side chain of the activated residue. This means that more 2-alkoxy-5(4//)-oxazolone and /V-acylurea are generated when the activated residues are hindered (see Section 1.4). A corollary of the above is that the best way to prepare an /V-acylurea, should it be needed, is to heat... 

In this way, the concept of donicity explains some properties of substances usually defined apolar from their usual parameters of polarity (dielectric constant, dipolar moment, Et parameter value) but which presents high possibilities of interaction (and of solvatation) with positively charged centres. This is the case of tertiary amines such as triethylamine (or of ethers such as THF, dioxane) which shows usual polarity parameters near that of apolar solvents (benzene, chloroform, chlorobenzene, 1,2-dichloroethane, etc.) but high ability to coordinate positive charges. 

Photoinduced intramolecular interaction of t-S and tertiary amine moieties linked with a polymethylene chain has also been studied24. The photoexcitation of fraws-stilbene in which a tertiary amine is attached to the ortho position with a (CH2)i-3 linker leads to fluorescent exciplexes by intramolecular electron transfer, and results in no more than trans-cis isomerization. The failure to give adducts from the intramolecular exciplexes could arise from the unfavourable exciplex geometry to undergo the necessary bond formation. 

E. Tertiary Amines as Donors in Intramolecular Charge Transfer Interaction... 

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