TEMPO‐Mediated Oxidative Deformylation of Aldehydes: Applications in the Synthesis of Polyketide Fragments

Abstract

A TEMPO‐mediated oxidative deformylation of aldehydes is reported that yields the TEMPO adducts, which can be further oxidized to the corresponding ketones. The focus of this work was on the optimization of a synthetic protocol for use in natural product synthesis, specifically for the preparation of chiral backbones with 1,2‐oxo functionalization found in polyketide antibiotics. In addition, the oxidative deformylation was combined with the oxidation of the alcohol to the precursor aldehyde in a one‐pot protocol.

A comprehensive insight into aldehyde deformylation: mechanistic implications from biology and chemistry

“…Please do not adjust margins Please do not adjust margins these examples, a 2,2,6,6-tetramethyl(piperidin-1-yl)oxyl (TEMPO)-mediated oxidative deformylation has been studied in aldehydes to give rise to alkoxyamines. 125 This is a one-pot reaction process combined with initial oxidation of the corresponding alcohols to aldehydes. Recently, alkyl halides were synthesized by visible light-mediated deformylative halogenation of aldehydes using inexpensive and atomeconomical halogen sources (NaBr, NaI, or HCl).…”

Expedient Synthesis of Long-Chain ω-Substituted Fatty Acids and Esters from Cyclic Ketones Using Iodine and Hydrogen Peroxide

“…This mechanistic scheme is similar to the previously reported cleavage of cyclohexanone with hydrogen peroxide and catalytic CuCl in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEM-PO). 9 Scheme 2 Mechanistic explanation of the formation of 6-iodohexanoic acid from cyclohexanone, H 2 O 2 , CuCl and iodine…”

Efficient covalent capping of carbon and gold with TEMPO for catalysis and spin writing

“…Immobilization of 2,2,6,6-tetramethyl piperidyl oxide (TEMPO) stable radicals at solid conducting supports is a key element in a large number of applications [1][2][3] related to interfaces with permanent magnetic character that are sought for sensing, 4 electronic, 5,6 energy storage, [6][7][8][9][10][11] catalysis, [12][13][14][15][16][17][18] biomedical, 11,19 and other fields. Two critical issues are to be dealt with here: (i) simple and reliable immobilization/fixation of TEMPO at the support and (ii) a long, chemically stable and atom-economical spacer attaching TEMPO to the support.…”

“…The thus prepared TEMPO-modified interfaces were probed for catalytic alcohol oxidation, one of the major applications of TEMPO. [12][13][14][15][16][17][18][31][32][33] The voltammetric responses of a gold (CH 2 ) 6 O-TEMPO-capped interface (in CH 3 CN/0.1 M Bu 4 NPF 6 ) in the presence of PhCH 2 OH (0.02 mol L À1 ) and 2,6-lutidine (0.08 mol L À1 ) used as a base well show all characteristic features of a catalytic process: increase of the current with respect to the response of the catalyst in the absence of the alcohol (Fig. 5A-C), disappearance of the reverse current of the reversible redox pair of the catalyst; and, seen for sharper shaped voltammograms (Fig.…”