Visible-Light-Mediated Anti-Markovnikov Hydration of Olefins

Abstract

Considering that stoichiometric borane and oxidant are required in the classical alkene anti-Markovnikov hydration process, it remains appealing to achieve the transformation in a catalytic protocol. Herein, a visible-lightmediated anti-Markovnikov addition of water to alkenes by using an organic photoredox catalyst in conjunction with a redox-active hydrogen atom donor was developed, which avoided the need for a transition-metal catalyst, stoichiometric borane, as well as oxidant. Both terminal and internal olefins are readily accommodated in this transformation to obtain corresponding primary and secondary alcohols in good yields with single regioselectivity. This procedure can be scaled up to gram scale with a 230 turnover number based on photocatalyst.

Light‐Driven Single‐Electron Transfer Processes as an Enabling Principle in Sulfur and Selenium Multicatalysis

“…In addition to various forms of carbon–heteroatom bond‐coupling reactions that follow the generic concept shown in Scheme , Nicewicz and co‐workers have recently extended their dual photoredox thiocatalysis concept to intermolecular carbon–carbon bond‐forming processes. For example, in a collaborative effort, Nicewicz, Huang, and co‐workers employed electron‐rich styrenes 64 as the 2π‐e − component in a series of [4+2] cross‐cycloaddition reactions with styrenes 65 to provide direct access to diversely substituted tetralin derivatives 66 (Scheme ) .…”

“…In addition to various forms of carbon-heteroatom bondcoupling reactions that follow the generic concept shown in Scheme 11, [45,48] Nicewicz and co-workers have recently extended their dual photoredox thiocatalysis concept to intermolecular carbon-carbon bond-forming processes.F or example,i nacollaborative effort, Nicewicz, Huang,a nd coworkers employed electron-rich styrenes 64 as the 2p-e À component in as eries of [4+ +2] cross-cycloaddition reactions with styrenes 65 to provide direct access to diversely substituted tetralin derivatives 66 (Scheme 12). [45i] Chemoselectivity (i.e.h etero-versus homodimerization) was attained through judicious combination of styrenes 64 with coupling partners 65 that possess markedly higher oxidation potentials.M ore specifically,t he most electron-rich styrene was proposed to preferentially undergo aS ET with photoexcited catalyst 62.The resulting radical cation 58 (e.g.…”

Lichtgetriebene Ein‐Elektronen‐Transferprozesse als Funktionsprinzip in der Schwefel‐ und Selen‐Multikatalyse

“…Neben den vielfältigen Varianten zur Knüpfung von Kohlenstoff‐Heteroatom‐Bindungen, die gemeinhin dem in Schema skizzierten Katalysekonzept folgen, gelang Nicewicz et al. vor kurzem die Erweiterung der dualen Photoredox/Thio‐Katalyse auf intermolekulare Reaktionen zur Knüpfung von Kohlenstoff‐Kohlenstoff‐Bindungen.…”

“…Ordnung fürd en exothermen SET (DG = À17 kcal mol À1 ) vom Akridinylradikal 63 auf das Thiylradikal in Hçhe von 3.1 10 9 m À1 s À1 ermittelt werden. [47] [45,48]…”

Visible-light-induced oxidant and metal-free dehydrogenative cascade trifluoromethylation and oxidation of 1,6-enynes with water

“…Alternatively, water can be added as a nucleophile to an organic substrate followed by its oxidation by weaker oxidants under light driven conditions, which could lead to the oxygenation of organic molecules. 21 …”