In 2019,Journal of the American Chemical Society included an article by Chen, Pan-Pan; Lucas, Erika L.; Greene, Margaret A.; Zhang, Shuo-Qing; Tollefson, Emily J.; Erickson, Lucas W.; Taylor, Buck L. H.; Jarvo, Elizabeth R.; Hong, Xin. Product Details of 70-55-3. The article was titled 《A Unified Explanation for Chemoselectivity and Stereospecificity of Ni-Catalyzed Kumada and Cross-Electrophile Coupling Reactions of Benzylic Ethers: A Combined Computational and Experimental Study》. The information in the text is summarized as follows:
Ni-catalyzed C(sp3)-O bond activation provides a useful approach to synthesize enantioenriched products from readily available enantioenriched benzylic alc. derivatives The control of stereospecificity is key to the success of these transformations. To elucidate the reversed stereospecificity and chemoselectivity of Ni-catalyzed Kumada and cross-electrophile coupling reactions with benzylic ethers, a combined computational and exptl. study is performed to reach a unified mechanistic understanding. Kumada coupling proceeds via a classic cross-coupling mechanism. Initial rate-determining oxidative addition occurs with stereoinversion of the benzylic stereogenic center. Subsequent transmetalation with the Grignard reagent and syn-reductive elimination produce the Kumada coupling product with overall stereoinversion at the benzylic position. The cross-electrophile coupling reaction initiates with the same benzylic C-O bond cleavage and transmetalation to form a common benzylnickel intermediate. However, the presence of the tethered alkyl chloride allows a facile intramol. SN2 attack by the benzylnickel moiety. This step circumvents the competing Kumada coupling, leading to the excellent chemoselectivity of cross-electrophile coupling. These mechanisms account for the observed stereospecificity of the Kumada and cross-electrophile couplings, providing a rationale for double inversion of the benzylic stereogenic center in cross-electrophile coupling. The improved mechanistic understanding will enable design of stereoselective transformations involving Ni-catalyzed C(sp3)-O bond activation. The experimental process involved the reaction of 4-Methylbenzenesulfonamide(cas: 70-55-3Product Details of 70-55-3)
4-Methylbenzenesulfonamide(cas: 70-55-3) belongs to anime. Nitrous acid converts secondary amines (aliphatic or aromatic) to N-nitroso compounds (nitrosamines): R2NH + HNO2 → R2N―NO. Some nitrosamines are potent cancer-inducing substances, and their possible formation is a serious consideration when nitrites, which are salts of nitrous acid, are present in foods or pharmaceutical preparations. Tertiary amines give rise to nitrosamines more slowly; an alkyl group is eliminated as an aldehyde or ketone, along with nitrous oxide, N2O.Product Details of 70-55-3
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics