N-heterocyclic carbene-catalyzed oxidation of aldehydes for the synthesis of amides via phenolic esters
作者:Miran Ji、Seungyeon Lim、Hye-Young Jang
DOI:10.1039/c4ra04012k
日期:——
N-heterocyclic carbene-catalyzedoxidationusingTEMPO is reported for the conversion of aldehydes to amides. A wide range of amides were synthesized in good yields (up to 72%) via a one-pot, sequential protocol involving oxidative esterification of aldehydes and subsequent aminolysis. To promote efficient aminolysis, various alkoxide leaving groups were evaluated.
This work describes acylation reactions facilitated by a type of heterocycle‐based acyl transfer agent, 2‐acyloxypyridazinone. Reactions of 2‐acyloxypyridazinone with carboxylic acids yield mixed carbonic anhydride intermediates, which are reactive and could be coupled with a wide range of substrates including acids, amines, alcohols, and thiols. The wide substrate scope, ease of operation (no additive
obtaining aryl esters from aliphatic primary alcohols and phenols was developed. The reaction proceeds under the irradiation of visible light at ambient temperature, dispensing with any oxidant or hydrogen acceptor. Primary alcohols having a variety of functional groups are successfully esterified with phenols. The produced esters can be utilized as the precursor of various carbonylcompounds.
One-pot dehydrogenation of carboxylic acid derivatives to α,β-unsaturated carbonyl compounds under mild conditions
作者:Jun-ichi Matsuo、Yayoi Aizawa
DOI:10.1016/j.tetlet.2004.11.106
日期:2005.1
Carboxylic acidderivatives such as N-acyl-2-oxazolidones, δ-lactones, and δ-lactams were smoothly dehydrogenated to the corresponding α,β-unsaturatedcarbonylcompounds in one-pot manner at −78 °C just by treating their lithium enolates with N-tert-butylbenzenesulfinimidoyl chloride.
Regioselective acylation of anisole with carboxylic acids over HZSM-5 catalyst
作者:Q. L. Wang、Yudao Ma、Xingdong Ji、Hao Yan、Qin Qiu
DOI:10.1039/c39950002307
日期:——
Over a HZSM-5 catalyst, the liquid-phase acylation of anisole with carboxylic acid gave the phenyl carboxylic ester at lower temperatures (< 403 K) while at higher temperatures (> 423 K) 4-acyl anisole was the predominant product.