Cleavage of C—N bond—

Exercise 23-43 Cleavage of C-N bonds by catalytic hydrogenation is achieved much more readily with diphenylmethanamine or triphenylmethanamine than with alkanamines. Explain why this should be so on the basis that the cleavage is a homolytic reaction. 

Tab. 3. Formation of C-H and C-C bonds upon reductive cleavage of C-N bonds. 

Cleavage of C-N bonds has been described elsewhere, for example, the reduction of g wj-dinitroalkanes to nitrite ion and nitroalkane anion [181,182] and f-nitroalkanes to nitrite and alkyl radical (Chapter 9) and the reduction of pyridylamines to picoline and ammonia (Chapter 18) [13,14] a rare case of a reductive loss of a nitro group from a benzene ring in l,2,4,5-tetrafluoro-3,6-dinitrobenzene has been reported [183]. Reduction of activated azides yields azide ion phenacyl azide is thus reduced to acetophenone and azide [236]. 

Hydrogenation of N-heterocycles -Hydrogenation of arene rings -Hydrogenolysis and cleavage of C-N bonds... 

The biogenetic origins of three groups of 3-alkylpiperidine alkaloids from bis-3-alkylpiperidine macrocyclic precursors is obscured by rearrangements in the carbon skeletons and hydrolytic cleavages of C-N bonds that are required to convert the macrocyclic precursors to the natural products. As a consequence, it is only possible to find one clearly defined 3-alkylpiperidine residue in the skeletons of these compounds. 

Hydrolytic cleavage of C=N bonds This reagent derived from nicotinic acid... 

Conventional phosphorescent OLEDs with CBP host in the EML and stable materials in blocking layers usually show better stability compared to triplet OLEDs with other host materials. Nevertheless, it was established that chemical mechanism of degradation in the CBP + Ir(ppy)3 devices is linked to homolytic cleavage of C-N bonds in CBP and includes several key steps such as the formation of CBP excited states, homolytic dissociation and formation... 

The rate-controlling step of the decomposition of HMX in the liquid phase is cleavage of C—N bonds [72]. 

FORMATION AND CLEAVAGE OF C—N BONDS IN ARGININE BIOSYNTHESIS AND UREA FORMATION... 

An efficient Cu(OTf)2-catalyzed 2,4,6-trisubstituted pyridine derivatives synthesis via C-N bond cleavage of aromatic methylamines and C(sp )-H bond activated of ketones was developed by Jiang s group (Scheme 8.80). A wide range of 2,4,6-trisubstituted pyridines could be obtained up to 95% yield at 100 °C under CU/O2 under this catalytic system with neat conditions. This process should be initiated by copper-catalyzed aerobic oxidative cleavage of C-N bond of aromatic methylamines [150]. 

Thermospray MS. This soft ionization technique is used in conjunction with HPLC. Under thermospray conditions, benzyldimethyldodecylammonium chloride and dodecylpyridinium chloride give a parent ion as well as protonated amines formed from cleavage of C-N bonds. The alkyl fragments are only seen with difficulty (122). 

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