N-H secondary amine

The addition reactions of It with amines are also presumed to occur via exciplex or radical-ion pair intermediates however, exciplex fluorescence is observed only under conditions where chemical reactions do not occur. Transfer of hydrogen from the amine a-C-H (tertiary amine) or N-H (secondary amine) bond results in the formation of a radical pair which ultimately gives rise to stilbene amine adducts and other free-radical derived products. The radical-ion pairs can also be intercepted by external electrophiles and nucleophiles, leading to formation of radical-ion-derived products. 

N-H for secondary amine as (R-NH-R) N-H (2v), secondary amine as (R-NH-R), diethylamine, first overtone band intensity comparisons, CCI4 solution N-H secondary amine ... 

N-H from primary, secondary, and tertiary amines N-H from amine salts... 

The photoreactions of anthracene [4] and stilbene [5] with amines have been reported by Yang in 1973 and Lewis in 1977, respectively. In 1974, Hixson found the photoreaction of 1,2-diphenylcyclopropane with primary and secondary amines, which gave the addition products [6], The electron-transfer quenching of the excited singlet of substrates with amines results in the formation of the exciplex or radical ion pair. These reactive species undergo proton transfer from a-C-H or N-H of amines... 

Primary and secondary amines are susceptible to oxidation and replacement reactions involving the N—H bonds. Within the development of peptide synthesis numerous protective groups for N—H bonds have been found (M, Bodanszky, 1976 L.A. Carpino, 1973), and we shall discuss five of the more general methods used involving the reversible formation of... 

Primary and secondary amines can participate m mtermolecular hydrogen bonding but tertiary amines lack N—H bonds and so cannot... 

These two vibrations are clearly visible at 3270 and 3380 cm in the IR spectrum of butylamine shown in Figure 22 la Secondary amines such as diethylamme shown m Figure 22 7i> exhibit only one peak which is due to N—H stretching at 3280 cm Ter tiary amines of course are transparent m this region because they have no N—H bonds... 

FIGURE 22 7 Portions of the IR spectra of (a) butyl amine and (b) diethylamme Primary amines exhibit two peaks due to N—H stretch mg m the 3300 to 3350 cm region whereas secondary amines show only one... 

Section 22 19 The N—H stretching frequency of primary and secondary amines appears m the infrared m the 3000-3500 cm region In the NMR spectra of amines protons and carbons of the type H—C—N are more shielded than H—C—O... 

H-Bond Acceptor-Donor (HBAD) Phenols Aromatic acids Aromatic amines Alpha H nitriles Iniines Monocarboj hc acids Other monoacids Peracids Alpha H nitros Azines Primary amines Secondary amines n-alcohols Other alcohols Ether alcohols... 

The diEFerent activation and deactivation influences are seen in 4,5-bromo-2-phenylpyridazin-3-one (209) which reacts with methoxide, hydrazine, or secondary amines at the 6-position. Related N—H and iV -alkyl halopyridazinones behave similarly. 

Mechanism of enamine formation by reaction of an aldehyde or ketone with a secondary amine, R2NH. The iminium ion intermediate has no hydrogen attached to N and so must lose H+ from the carbon two atoms away. 

In addition to their behavior as bases, primary and secondary amines can also act as very weak acids because an N-H proton can be removed by a sufficiently strong base. We ve seen, for example, how diisopropylamine (pK-A 40) reacts with butyilithium to yield lithium diisopropylamide (LDA Section 22.5). Dialkylamine anions like LDA are extremely powerful bases that are often used... 

Primary and secondary amines can be identified by a characteristic N—H stretching absorption in the 3300 to 3500 cm"1 range of the IR spectrum. Alcohols also absorb in this range (Section 17.11), but amine absorption bands are generally sharper and less intense than hydroxyl bands. Primary amines show a pair of bands at about 3350 and 3450 cm-1, and secondary amines show a single band at 3350 cm-1. Tertiary amines have no absorption in this region because they have no N-H bonds. An IR spectrum of cyclohexylamine is shown in figure 24.7. 

Coniine, C H N. is the toxic principle of the poison hemlock drunk by Socrates. When subjected to Hofmann elimination, coniine yields 5-(iV,N-dimethylamino)-l-octene. If coniine is a secondary amine, what is its structure ... 

H NMR data has been reported for the ethylzinc complex, Zn(TPP—NMe)Et, formed from the reaction of free-base N-methyl porphyrin H(TPP—NMe) with ZnEti. The ethyl proton chemical shifts are observed upheld, evidence that the ethyl group is coordinated to zinc near the center of the porphyrin. The complex is stable under N2 in the dark, but decomposed by a radical mechanism in visible light.The complex reacted with hindered phenols (HOAr) when irradiated with visible light to give ethane and the aryloxo complexes Zn(TPP—NMe)OAr. The reaction of Zn(TPP—NMe)Et, a secondary amine (HNEt2) and CO2 gave zinc carbamate complexes, for example Zn(TPP—NMclOiCNEti."" ... 

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