Dialkylamino groups

A rigidized molecule obtained when the two a-carbons of the trimethine chain are linked by a dimethylene bridge cannot be planar. According to the resonance concept, its stability increases as a bathochromic effect of 41 nm is observed (122). The of the bistyryl dye obtained by the substitution of the -proton in the chain of a styryl dye by a dialkylamino group is nearly the same as for the parent styryl dye (123). 

The reaction of dialkylaminobutenynes with 1,2- and 1,3-dimercaptoalkanes also involves the formation of adducts of 1,3-orientation (85USSRP1109401 88ZOR88), but with retention of the initial butenyne dialkylamino group, in contrast to the reaction with 1,2-diaminoethane. Thus, with 1,2-dimercaptoethane, 1-dialkylaminobut- l-en-3-ynes form 7-dialkylamino-5-methyl-7//-2,3-dihydro-1,4-dithiepins (105) in 90-96% yield (85USSRP1109401 88ZOR88). 

Thus, ynaminoketones with 1,2-diaminobenzene form benzodiazepines with retention of the dialkylamino group. The reaction occurs as a nucleophilic addition in the absence of catalysts. With Q, /3-acetylenic ketones 1,2-diaminobenzene reacts in the same manner, but under proton-catalyzed conditions (72LA24). At the same time, ynamines and enynamines furnish with 1,2-diaminobenzene substituted benzimidazoles as aresultof double attack at the acetylene bond(83ZOR926 84ZOR1648). 

Other substituents Alkjd of p-dialkylamino group Mp (°C) of isopropylidene derivative Mp C C) of benzylidene derivative... 

Structural hybrid, in resonance theory. 69 Structures, of dyes, in relation with elecuo-chemical potential. 75 extreme of cyanine dyes, 69 Styryl compounds, nomenclature of, 29 Styryl dyes, in basicity scale, 71 with dialkylamino group, 77 as models in relation with pKa, 50 and role of anhvdrobases. 50 as sensitizers, in photography. 79 stereo aspect of condensation. 50 synthesis of, 49... 

Fluoran compounds having a dialkylamino group at 3 -position generally develop color from yellowish red to vermilion. These include... 

The electrochemical oxidation of monoolefins bearing electron-donating substituents such as alkoxy, acyloxy or dialkylamino group takes place more easily than that of simple monoolefins, and products formed by the addition of a nucleophile to the double bond are obtained with satisfactory yields4. 

In a similar approach, the HOMO level of PPV was controlled by the introduction of a dialkylamino donor group (polymer 64) [120] (Chart 2.12). The dialkylamino groups render... 

Azatriboretidines 70 and 71 (Scheme 36) are stable because the electron deficit is compensated by exo-cyclic dialkylamino groups, but their aromaticity has not been proven.94... 

D. la Intramolecular attack by the dialkylamino-group on a neighbouring ester group 254, D.lb Intramolecular nucleophilic attack by imidazole and pyridine 255, D.2 Intramolecular attack by the NHR group 256, D.3 The cyclization of halogeno-amines, etc. 256, D.4 Intramolecular nucleophilic attack on phosphorus 259... 

D. 1 a Intramolecular attack by the dialkylamino-group on a neighbouring ester group... 

Scheme 3.2-31. The framework atoms C4B2 prefer classical structures (e.g., 58 or 60) if dialkylamino groups are linked to both boron atoms. Note also the rearrangement of the...

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