- Catalytic Regioselective Olefin Hydroarylation(alkenylation) by Sequential Carbonickelation-Hydride Transfer
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Alkene hydrocarbofunctionalization represents one of the most important classes of chemical transformations, but related branched-selective examples with unactivated olefins are scarce. Here, we report that catalytic amounts of a dimeric Ni(I) complex and an exogenous alkoxide base promote Markovnikov-selective hydroarylation(alkenylation) of unactivated and activated olefins using organo bromides or triflates derived from widely available phenols and ketones. Products bearing aryl- and alkenyl-substituted tertiary and quaternary centers could be isolated in up to 95% yield and >99:1 regioisomeric ratios. Contrary to previous dual-catalytic methods that rely on metal-hydride atom transfer (MHAT) to the olefin prior to carbofunctionalization with a cocatalyst, our mechanistic evidence points toward a nonradical reaction pathway that begins with site-selective carbonickelation across the C═C bond followed by hydride transfer using alkoxide as the hydride source. Utility of the single-catalyst protocol is highlighted through the synthesis of medicinally relevant scaffolds.
- Liu, Chen-Fei,Luo, Xiaohua,Wang, Hongyu,Koh, Ming Joo
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supporting information
p. 9498 - 9506
(2021/07/19)
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- Metal-free coupling of saturated heterocyclic sulfonylhydrazones with boronic acids
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The coupling of aromatic moieties with saturated heterocyclic partners is currently an area of significant interest for the pharmaceutical industry. Herein, we present a procedure for the metal-free coupling of 4-, 5-, and 6-membered saturated heterocyclic p-methoxyphenyl (PMP) sulfonylhydrazones with aryl and heteroaromatic boronic acids. This procedure enables a simple, two-step synthesis of a range of functionalized sp2-sp3 linked bicyclic building blocks, including oxetanes, piperidines, and azetidines, from their parent ketones.
- Allwood, Daniel M.,Blakemore, David C.,Brown, Alan D.,Ley, Steven V.
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p. 328 - 338
(2014/01/17)
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