Efficient and Highly Selective Oxidation of Primary Alcohols to Aldehydes by N-Chlorosuccinimide Mediated by Oxoammonium Salts

Abstract

2,2,6,6-Tetramethyl-1-piperidinyloxy catalyzes efficient oxidation of primary alcohols to aldehydes by N-chlorosuccinimide, in a biphasic dichloromethane-aqueous pH 8.6 buffer system in the presence of tetrabutylammonium chloride. Aliphatic, benzylic, and allylic alcohols are readily oxidized with no overoxidation to carboxylic acids. Secondary alcohols are oxidized to ketones with a much lower efficiency. Very high chemoselectivities are observed when primary alcohols are oxidized in the presence of secondary ones. Primary-secondary diols are selectively transformed into hydroxy aldehydes, with, in some cases, no detectable formation of the isomeric keto alcohols.

Nitroxide decomposition: Implications toward nitroxide design for applications in living free‐radical polymerization

“…These unusual properties have led to a wide range of applications spanning their use in biology as spin labels [1][2][3][4][5][6] to the development of organomagnetic materials. 7 In organic chemistry, nitroxides have been used in kinetic studies, [8][9][10][11] as oxidizing species in the form of the corresponding N-oxo ammonium salts, [12][13][14][15][16][17][18][19][20][21][22][23] as temporary caps for transient carbon radicals, [24][25][26][27][28][29][30][31] and as probes for stereocontrol with prochiral carbon radicals. [32][33][34][35][36] In polymer chemistry, nitroxide-mediated polymerization (NMP) [37][38][39][40][41][42][43][44][45][46][47] has become popular as a method for preparing living polymers ...…”

Abietane Lactones and Iridoids from Goldfussia yunnanensis

“…The Acid Hydrolysis of 3-6 Compound 3 (10 mg) was dissolved in MeOH (0.5 ml) and then heated with 2 M HCl (2 ml, aq.) at 70°C for 3 h. After 5 ml of H 2 O was added and the mixture was extracted with EtOAc (3ϫ5 ml), the aqueous phase was evaporated under reduced pressure repeatedly by adding CH 3 Conversion of Compounds 1 and 2 to Helioscopinolide A The oxidation of compound 1 was performed according to the method described by Einhorn et al 7) To a solution of compound 1 (0.1 mmol, 33.2 mg), 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) (0.01 mmol, 1.6 mg), and tetrabutylammonium chloride (TBACl) (0.01 mmol, 2.8 mg) in 2.5 ml of dichloromethane, and 2.5 ml of an aqueous solution of NaHCO 3 (0.5 M) and K 2 CO 3 (0.05 M) was added N-chlorosuccinimide (NCS, 0.15 mmol, 20.0 mg) under stirring at 35-37°C. The reaction was monitored by TLC.…”

New One-Pot Synthesis of 4-Hydroxybenzaldehyde Derivatives and Picric Acid from 4-Hydroxyphenylglycine with HNO3/H2O

“…NaCN and super acidic conditions (F 3 CSO 2 OH-SbF 5 ), 5 while various oxidizing agents, such as Na2Cr2O7 in water, 6 K2Cr2O7 in DMF, 7 CrO3 on silica gel, 8 NCS-TEMPO, 9 tetrapropylammonium perruthenate (TPAP) 10 and nitroxyl radical oxidaizing agent, 11 have been utilized to convert primary alcohols to aldehydes.…”