ISSN:
0268-2605
Keywords:
Dimerization
;
aldehyde
;
carboxylic ester
;
pentacarbonylchromate
;
synthesis
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Na2[Cr(CO)5] (1) was found to be an efficient catalyst for the dimerization of aldehydes to carboxylic esters. Several aromatic aldehydes including furfural gave the corresponding esters in good yields. This reaction also proceeded intramolecularly to give phthalide from phthalaldehyde. Compared with M2[Fe(CO)4] (M = Na, K), 1 was found to be a more efficient catalyst for this reaction. However, aliphatic aldehydes gave aldolcondensation products instead of the corresponding esters. In the reactions of p-substituted benzaldehydes with 1, the reactivity decreased with the increase of the electron-releasing ability of the substituents. However, even p-anisaldehyde, which hardly reacted with M2[Fe(CO)4], reacted with 1 to give the ester in moderate yield. The reaction mechanism, including the nucleophilic attack of the pentacarbonylchromate dianion on the carbonyl carbon, is discussed.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aoc.590080205
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