No acidic or basic reagents are used during the reaction. No chromatographic separation is required for isolation of the acylated products. Reactions in a neutral aqueous medium, easy isolation of products, and innocuous by-products make the present method a green chemical process. (? Wiley-VCH ...
Amines are organic compounds that are derived from ammonia and are basic in nature. Amines are present in amino acids, the building units of protein hence present in DNA, hormones and neurotransmitters. Amines are classified as primary, secondary and tertiary and can be identified through unique r...
Electron transfer likely occurred upon the interaction of acidic and basic sites. Figure 4b illustrates the differential charge density distribution upon binding primary, secondary, and tertiary amines with Cr sites, indicating substantial electron density redistribution within PEI. Interestingly, electron ...
Vinylamide oligomers and lower molecular weight polymers are prepared by the cationic polymerization of vinylamides in the presence of a Lewis acid at a temperature between -100° and 100° C. The resultant vinylamide oligomers and polymers can optionally be hydrolyzed under acidic or basic ...
amines (胺类)
(PTCPs). The results of a subsequent analysis demonstrated that PTCP neutralized the acidic microenvironment to enhance adhesion, proliferation, and bone regeneration owing to the activity of BHEp. Therefore, some SMAs can not only serve as a unit of a base material that enhances the physical ...
Both are surface-active substances. Primary long-chain ammonium salts are derived from the weakly basic aliphatic amines. Because quats are salt bases, they remain in solution in acidic as well as in basic media. Among the many quaternary ammonium salts available: benzalkonium chloride, alkylbenzyl...
This property is usually observed for acidic cationic surfactants due to the special environment of the surfactant head-groups close to the micelle surface. It is the conjugate base, n-C12NH2, that separates from the aqueous solution and makes it cloudy at pH≈6.5. Suppose that the average ...
secondary amines give alkali-insoluble N,N-dialkyl benzenesul-fonamides,and tertiary amines do not react un-der these conditions.Limitations can arise with long-chain primary amines,which are alkali-insoluble despite their acidic hydrogen,and with tertiary amines,which may undergo quaterniza-tion with...
triisopropoxide and aluminium foil are converted under the reac- tion conditions to an active Lewis acid co-catalyst that activates the nitrile group. These Lewis acidic centres can probably also be gener- ated on the silica support close to the nanoparticles by reaction with Si–OH sites on ...