Rhodium-Catalyzed Room Temperature C–C Activation of Cyclopropanol for One-Step Access to Diverse 1,6-Diketones
摘要:
A rhodium-catalyzed room temperature C-C activation of cyclopropanol has been demonstrated for the single-step synthesis of a range of electronically and sterically distinct 1,6-diketones. This reaction proceeds efficiently in shorter reaction time following a highly atom-economical pathway. To illustrate the synthetic potential of 1,6-diketones, aldol and macrocyclization reactions have been successfully demonstrated. Preliminary mechanistic studies revealed the involvement of nonradical pathways.
Palladium-catalyzed cross-coupling of cyclopropanol-derived ketone homoenolates with aryl bromides
作者:David Rosa、Arturo Orellana
DOI:10.1039/c3cc42080a
日期:——
The cross-coupling reaction of cyclopropanol-derived ketone homoenolates bearing β-hydrogens with aryl and hetaryl bromides has been achieved for the first time. This reaction is high yielding, is broad in scope and uses a simple catalytic system. Notably, the proposed palladium homoenolates do not undergo β-hydride elimination to the corresponding α,β-unsaturated ketones.
Copper(I)-Catalyzed Chemoselective Coupling of Cyclopropanols with Diazoesters: Ring-Opening C−C Bond Formations
作者:Hang Zhang、Guojiao Wu、Heng Yi、Tong Sun、Bo Wang、Yan Zhang、Guangbin Dong、Jianbo Wang
DOI:10.1002/anie.201612138
日期:2017.3.27
Reported herein is an exceptional chemoselective ring‐opening/C(sp3)−C(sp3) bond formation in the copper(I)‐catalyzed reaction of cyclopropanols with diazo esters. The conventional O−H insertion product is essentially suppressed by judicious choice of reaction conditions. DFT calculations provide insights into the reaction mechanism and the rationale for this unusual chemoselectivity.
a uracil-copper catalytic system was developed to promote ring-opening allylation of cyclopropanols with allylic alcohols under water-tolerant conditions. A new C–OH bond-breaking model can well resolve the trade-off between the need for acidic activators for C(allyl)–OH bond cleavage and the demand for strong basic conditions for generating homoenolates. Therefore, Morita–Baylis–Hillman alcohols,
受铜与 DNA 和 RNA 的高亲和力的启发,开发了尿嘧啶-铜催化系统,以促进环丙醇与烯丙醇在耐水条件下的开环烯丙基化。一种新的C-OH键断裂模型可以很好地解决C(烯丙基)-OH键断裂所需的酸性活化剂与生成同烯醇盐所需的强碱性条件之间的权衡。因此,Morita-Baylis-Hillman 醇,而不是它们的预活化版本,可以直接掺入与环丙醇的脱水交叉偶联中,产生水作为唯一的副产物。多种功能化的δ 、 ε-不饱和酮以良好到高的收率和高E-选择性获得。
Palladium-Catalyzed Cross-Coupling of Benzyl Chlorides with Cyclopropanol-Derived Ketone Homoenolates
作者:Nisha Nithiy、Arturo Orellana
DOI:10.1021/ol5027188
日期:2014.11.21
The palladium-catalyzed cross-coupling reaction of cyclopropanol-derived ketone homoenolates with benzyl chlorides is reported. This reaction proceeds in high yields with electron-neutral and electron-rich benzyl chlorides; however, yields are low with electron-poor benzyl chlorides. In addition, a range of cyclopropanols can be coupled in good yields. The reaction can be conducted with a low catalyst loading (1% Pd) and on a gram scale without reduction in yield.
One-Step Synthesis of Quinolines via Palladium-Catalyzed Cross-Coupling of Cyclopropanols with Unprotected ortho-Bromoanilines
作者:Arturo Orellana、Andrei Nikolaev、Nisha Nithiy
DOI:10.1055/s-0034-1378613
日期:——
The cross-coupling of unprotected ortho-bromoanilines with cyclopropanols yields quinolines in a single operation via an intramolecular condensation and palladium-catalyzed oxidation sequence. The reaction tolerates a variety of cyclopropanols and substituted bromoanilines. Deuterium-labeling experiments provide direct evidence of a second equivalent of bromoaniline serving as the terminal oxidant.