A novel methodology for the synthesis of 1,5-diketones through a one-pot isomerization–methylenation of a variety of allylicalcohols has been established for the first time. This methodology utilizes commercially available palladium acetate and easily accessible BINOL phosphoric acid. Both isomerization of allylicalcohol and oxidation of methanol occurred through a single catalyst. The practical
首次建立了一种通过多种烯丙醇的单锅异构化-亚甲基化合成 1,5-二酮的新方法。该方法使用市售的醋酸钯和易于获取的 BINOL 磷酸。烯丙醇的异构化和甲醇的氧化都是通过单一催化剂发生的。该方法的实际效用已通过连续加成合成取代的吡啶来证明。机理研究表明,烯丙醇异构化为相应的酮,最终进行甲基化,生成 1,5-二酮,其中 H 2和 H 2 O 作为唯一的副产物。
Base-Mediated Cascade Rearrangements of Aryl-Substituted Diallyl Ethers
作者:Jolene P. Reid、Catherine A. McAdam、Adam J. S. Johnston、Matthew N. Grayson、Jonathan M. Goodman、Matthew J. Cook
DOI:10.1021/jo502403n
日期:2015.2.6
Two base-mediated cascade rearrangement reactions of diallyl ethers were developed leading to selective [2,3]-Wittig–oxy-Cope and isomerization–Claisen rearrangements. Both diaryl and arylsilyl-substituted 1,3-substituted propenyl substrates were examined, and each exhibits unique reactivity and different reaction pathways. Detailed mechanistic and computational analysis was conducted, which demonstrated
synthesis of N-cyanomethyl amides from allylic alcohols with AIBN as the nitrile source is developed. Owing to the coordination effect with the copper catalyst, a ketenimine intermediate is formed via couplings of isobutyronitrile radicals. The copper-activated ketenimine could subsequently be intercepted by allylic alcohols and undergo Claisen rearrangement to furnish N-cyanomethyl amides. Further
[GRAPHICS]The high level of catalyst performance was attainable in the palladium-catalyzed 1,2-addition of aryl-, heteroaryl-, and alkenylboronic acids to aromatic, heteroaromatic, and aliphatic aldehydes using thioether-imidazolinium chloride L5 as a heterobidentate carbene ligand precursor.
Palladium-Catalyzed 1,2-Addition of Potassium Aryl- and Alkenyltrifluoroborates to Aldehydes using Thioether−Imidazolinium Carbene Ligands
Palladium-catalyzed 1,2-addition of potassium aryl- and alkenyltrifluoroborates to aldehydes using thioether-imidazolinium carbene ligands proceeded readily under aqueous conditions. This process tolerated a diverse range of potassium trifluoroborate salts and aldehydes, giving a variety of carbinol derivatives with good to excellent yields.