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.
A metal-free method for formal β-arylation/heteroarylation of ketones through efficient cyclopropanol ring-opening cross-couplings with aryl sulfoxides at room temperature has been developed. This protocol shows a broad substrate scope and promising scalability. In addition, the utility of the β-arylated ketones is further demonstrated through a variety of postcoupling transformations and synthetic
Utility of Organoboron Reagents in Arylation of Cyclopropanols via Chelated Pd(II) Catalysis: Chemoselective Access to β-Aryl Ketones
作者:Thangeswaran Ramar、Murugaiah A. M. Subbaiah、Andivelu Ilangovan
DOI:10.1021/acs.joc.0c00160
日期:2020.6.19
Organoborane reagents were investigated as coupling partners to cyclopropanol-derived β-ketone enolates in the presence of a chelated Pd(II) catalyst. Efficient coupling of a range of electronically and sterically diverse cyclopropanols and aryl/alkenyl boronic derivatives (39 examples, 65–94% yield) could be achieved with the generation of synthetically important β-aryl ketone intermediates in a chemoselective
A copper(I)-catalyzed ring-opening cyanation of cyclopropanols was developed. The reaction provides an alternative method to achieve β-cyano ketones efficiently. This reaction exhibits good functional group compatibility under mild conditions and can be scaled up to the gram scale. Preliminary mechanistic studies suggest that the reaction might go through a free radical process.
Orchestrating a β-Hydride Elimination Pathway in Palladium(II)-Catalyzed Arylation/Alkenylation of Cyclopropanols Using Organoboron Reagents
作者:Thangeswaran Ramar、Murugaiah A. M. Subbaiah、Andivelu Ilangovan
DOI:10.1021/acs.joc.1c02735
日期:2022.4.1
scope of chemoselective β-hydride elimination in the context of arylation/alkenylation of homoenolates from cyclopropanol precursors using organoboronic reagents as transmetalation coupling partners was examined. The reaction optimization paradigm revealed a simple ligand-free Pd(II) catalytic system to be most efficient under open air conditions. The preparative scope, which was investigated with
Site‐ and Stereoselective C(
<i>sp</i>
<sup>3</sup>
)−H Borylation of Strained (Hetero)Cycloalkanols Enabled by Iridium Catalysis
作者:Qian Gao、Senmiao Xu
DOI:10.1002/anie.202218025
日期:2023.2.13
(CBL) and iridium precursor was found effective in catalyzing carbamate-directed C(sp3)−Hborylation of strained (hetero)cycloalkanols in a site- and stereoselective manner. This method features broad substrate scope (>50 examples), excellent site-selectivity, and high enantioselectivity (up to 95 % ee), providing a robust protocol for access to diverse, densely substituted (hetero)cycloalkanols.