One-Pot Synthesis of Carbamoyl Azides Directly from Primary Alcohols and Oxidation of Secondary Alcohols to Ketones Using Iodobenzene Dichloride in Combination with Sodium Azide
作者:Xiao-Qiang Li、Wei-Kun Wang、Chi Zhang
DOI:10.1002/adsc.200900428
日期:2009.10
An effective synthesis of carbamoyl azides directly from primary alcohols using iodobenzenedichloride in combination with sodium azide has been developed. Moreover, the same regent combination was also efficient for the oxidation of secondary alcohols to the corresponding ketones.
(DPPA). The reactionprocedure is quite simple, occurring by refluxing an equimolecular mixture of a carboxylic acid, DPPA, and triethylamine in the presence of a hydroxyl component. Aromatic, aliphatic, and heterocyclic carboxylic acids underwent rearrangements in satisfactory yields. As this modified Curtins reaction is much simpler and less laborious than the classical Curtius reaction and proceeds
作者:Lavinia Marinescu、Jacob Thinggaard、Ib B. Thomsen、Mikael Bols
DOI:10.1021/jo035163v
日期:2003.11.1
Aliphatic and aromatic aldehydes can be converted to acyl azides by treatment with iodine azide at 0-25 degrees C. If the reaction is performed at reflux Curtiusrearrangement occurs and carbamoylazides are obtained in 70-97% yield from the aldehyde. The reaction was shown to have a radical mechanism.
Treatment of amines under a carbon dioxide atmosphere with tetramethylphenylguanidine (PhTMG) and diphenylphosphoryl azide (DPPA) in acetonitrile below 0 °C provides carbamoyl azides in high to excellent yields. In addition, epimerization is not observed when optically pure α-amino esters are used as substrates.
A novel method was developed for the synthesis of carbamoyl azides from hydroxamic acids via the Lossen rearrangement using diphenyl phosphorazidate, which acts as both the activator and azide source to produce the azidesvia an isocyanate intermediate. Using this method, various hydroxamic acids were converted into the corresponding carbamoyl azides, enabling their preparation without the use of highly