Catalytic Synthesis of Aldehydes and Ketones under Mild Conditions Using TEMPO/Oxone

Abstract

[formula: see text] A novel, metal-free oxidation system for the catalytic synthesis of aldehydes and ketones--TEMPO/Oxone--has been developed. An optimized reaction protocol proved especially successful for the synthesis of ketones. Additionally, the influence of quarternary ammonium salts on the catalysis was studied. The mild conditions of this novel procedure were shown to tolerate even sensitive silyl protective groups which can otherwise be cleaved in the presence of Oxone.

Discovery and Exploitation of AZADO: The Highly Active Catalyst for Alcohol Oxidation

“…[4][5][6][7][8][9][10][11] In recent years, a stable class of nitroxyl radicals, 12) as exemplified by 2,2,6,6-tetramethyl piperidinyl 1-oxyl (TEMPO) [(1); Chart 1], has extensively been used as a catalyst for oxidation of alcohols, because TEMPO is readily available from chemical suppliers at a reasonable price, and because the method allows the use of various safe bulk oxidants, thereby offering safe and extremely efficient oxidation of alcohols with considerable operational simplicity. [13][14][15][16][17][18][19][20][21][22][23][24][25] Today, TEMPOcatalyzed alcohol oxidation has high priority not only in academic laboratories, but also in the chemical industries, particularly in the pharmaceutical industry, as an efficient, mild, and environmentally acceptable method.…”

Utilização do TEMPO (N-oxil-2,2,6,6-tetrametilpiperidina) na oxidação de álcoois primários e secundários

“…Um eficiente método de oxidação de álcoois em cetonas utilizando o TEMPO como catalisador foi realizado por Bolm e colaboradores 30 , que empregaram OXONO (peróxidomonosulfato de potássio 2KHSO 5 .KHSO 4 .K 2 SO 4 ) como co-oxidante, bem como um sal de amônio quaternário (n-Bu 4 NBr) (Esquema 9). Este método é extremamente brando, podendo tolerar grupos funcionais sensíveis como os grupos sililas.…”

Synthesis, Characterization of Cellulose Grafted N-Oxide Reagent and Its Application in Oxidation of Alkyl/Aryl Halides

“…Efficient methods for the conversion of alcohols to aldehydes, ketones or carboxylic acids under mild conditions have been developed, using TEMPO (2,2,6, 6-tetramethyl-1-piperidinyloxy), (I), as a catalyst and （I） stoichiometric amounts of inexpensive, safe and easy to handle oxidants such as bleach [2], [bis(acetoxy) iodo] benzene (BAIB) [3], trichloroisocyanuricacid (TCCA) [4], oxone [5] or iodine [6].…”