10.1021/jo991328h
The research focuses on the efficient kinetic resolution in the asymmetric hydrosilylation of imines of 3-substituted indanones and 4-substituted tetralones, utilizing a chiral titanocene catalyst. The purpose of this study was to achieve high enantiomeric excess (ee) and diastereomeric purity in the synthesis of ketones and amines, which are crucial for the production of bioactive and pharmaceutically interesting molecules, such as the antidepressant sertraline. The researchers successfully demonstrated that N-methyl imines of 4-substituted tetralones could be resolved to yield ketones with high ee's and amine products with high diastereomeric and enantiomeric purity. Key chemicals used in the process include phenylsilane as the stoichiometric reductant, (EBTHI)titanocene catalyst, and various imine substrates derived from 3-substituted indanones and 4-substituted tetralones. The study concluded that the methodology could be applied to the enantiomeric synthesis of sertraline, an important antidepressant, with high diastereoselectivity and enantioselectivity.
10.1021/acscatal.6b03373
The research study on the control of selectivity in cobalt-catalyzed hydrosilylation of dienes and terminal alkenes through the synergy between catalysts, silanes, and reaction conditions. The purpose of the study was to develop a method for highly selective anti-Markovnikov hydrosilylation of terminal double bonds in 1,3- and 1,4-dienes, as well as terminal alkenes, using readily accessible (i-PrPDI)CoCl2 as the catalyst and primary or secondary silanes such as PhSiH3, Ph2SiH2, and PhSi(Me)H2. The research concluded that by optimizing the reaction conditions, it was possible to achieve high selectivity in anti-Markovnikov hydrosilylation, with the product ratio favoring the anti-Markovnikov product as the size of the 2,6-substituents in the iminoylaryl group increased.
10.1002/anie.201713285
The study titled "Reductive Carbocyclization of Homoallylic Alcohols to syn-Cyclobutanes via Boron-Catalyzed Dual Ring-Closing Pathway" explores a novel method for synthesizing 1,2-disubstituted arylcyclobutanes through an organoborane-catalyzed reductive carbocyclization process. The key chemicals involved are homoallylic alcohols and their O-silyl ethers, which act as the substrates for the cyclobutanation reaction. Hydrosilanes, specifically EtMe2SiH and PhSiH3, serve as reducing agents, while B(C6F5)3 functions as the catalyst. The reaction proceeds in a cis-selective manner under mild conditions, yielding cyclobutanes with high efficiency and excellent selectivity. Mechanistic studies, including deuterium scrambling, Hammett studies, and DFT calculations, support a dual ring-closing pathway involving carbocation rearrangements. The study demonstrates the versatility of the method by testing various substrates, including those with functional groups like phenoxy and thioether, and shows that the olefinic geometry of the substrates does not affect the stereochemistry of the product. The findings highlight a powerful alternative to conventional methods for synthesizing four-membered carbocycles, offering a mild, efficient, and selective route to produce cyclobutanes and cyclopentanes.
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