Hydrogen bromide (HBr) adds across a carbon–carbon double bond (CC) to form the corresponding alkyl bromide, in which the hydrogen ends up on the carbon atom that had more hydrogen atoms to begin with. Addition of HBr to 2-butene, for example, gives 2-bromobutane: Sign in to download ...
They undergo acylation with carboxylic acid esters, anhydrides and acyl chlorides; C-alkylation with alkyl bromides and iodides; and hydroxyalkylation with aldehydes and ketones (Scheme 9).48 This variant of the nitroaldol reaction proceeds in better yields than classical Henry procedures, especially ...
Caffeine has a tertiary amine group with three alkyl groups and an amide group in which a carboxyl group is connected to a nitrogen atom. In addition to these groups, imine, carboxyl, methyl, and alkene groups are also present in caffeine. The carbon–oxygen and carbon–nitrogen covalent ...
alkene. The number of moles of base required for the reaction depends on the type of alkyne produced. A terminal alkyne produced in the synthesis is deprotonated by the reacting base, and thus a total of three moles of amide ion is required. Upon work up with water, the terminal alkyne ...
Deprotonation of 43+a–c afforded the functionalized heterocycles 44a–c in satisfactory yields (Scheme 6.24). In the presence of different fluorinated radical precursors (e.g., fluoroalkylbromides), the corresponding fluoroalkylated pyridines were also efficiently isolated [80]. On the other hand,...
Termination via chain transfer, either by β-hydrogen (β-H) transfer or transfer to alkylaluminium species, is often observed in metallocene-based polymerization reactions [1]. As a result, the produced polymers have high PDIs, where conventional multi-site Ziegler-Natta catalysts yield PDIs of ...
6.1. Macrocycles with endo aryl-aryl and aryl-alkyl ether bond Macrocycle with an endo aryl-aryl ether bond has been found as a key structure unit in a number of natural products, such as vancomycin, an architecturally complex and medicinally important glycopeptide antibiotic, Fig. 2. Being awa...
A direct observation of the Criegee intermediate in the gas-phase has been achieved by a combination of tunable synchrotron photoionization with multiplexed mass spectrometry [63]. Recent calculations credited formaldehyde oxide with considerable zwitterionic character [64], and show that alkyl substitution...
16. The method of claim 1, wherein said N-hydroalkyl-p-phenylenediamine derivative is 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline salt. 17. The method of claim 1, wherein an amount of a developer replenishment is not more than 250 ml per m2 of the silver halide light-sensitive...
The enzyme reaction can be performed across a broad range of pH, dependent on enzyme activity and stability at a given pH, and on the substrate specificity for perhydrolysis at a given pH. Esterases, lipases, and some proteases have the ability catalyze the hydrolysis of alkyl esters to ...