释义 |
Knoevenagel Chem.|ˈknœvənɑːgəl| The name of Emil Knoevenagel (1865–1921), German chemist, used attrib. and occas. in the possessive to designate various reactions in organic chemistry, esp. the reaction between an aldehyde or ketone and malonic acid or a related compound containing active hydrogen, catalysed by ammonia or an amine, to yield an acid with the group {b1}CH·CH·COOH.
1907J. B. Cohen Org. Chem. Adv. Students I. vii. 285 (heading) Knoevenagel's reaction. 1931Jrnl. Chem. Soc. 745 Catalytic action..effected by the salts of bases with mineral acids in the malonic acid condensation and the Knoevenagel reaction generally. 1938G. H. Richter Textbk. Org. Chem. xvi. 289 The Knoevenagel reaction is the condensation of the carbonyl group of aldehydes and ketones with active methylene hydrogens; the reaction takes place in the presence of primary and secondary amines, especially diethylamine or piperidine. Knoevenagel was the first to point out the great catalytic power of ammonia and amines for this type of condensation. 1967Organic Reactions XV. 204 (heading) The Knoevenagel condensation. 1969R. C. Denney Named Org. Reactions 52 An interesting development has been the use of the Knoevenagel condensation to increase the chain length of sugars. |