Photoinduced Cross-Coupling of Aryl Iodides with Alkenes
作者:Yuliang Liu、Haoyu Li、Shunsuke Chiba
DOI:10.1021/acs.orglett.0c03935
日期:2021.1.15
A protocol for photoinduced cross-coupling of aryliodides having polar π-functional groups or elongated π-conjugation with alkenes has been developed. The radical cascade mechanism involving generation of aryl radicals via C–I bond homolysis of photoexcited aryliodides and their subsequent addition to alkenes is proposed. The method enables iodide-selective cross-coupling over other halogen leaving
Pd(OAc)<sub>2</sub>/P(<i><sup>c</sup></i>C<sub>6</sub>H<sub>11</sub>)<sub>3</sub>-Catalyzed Allylation of Aryl Halides with Homoallyl Alcohols via Retro-Allylation
fashion via a conformationally regulated six-membered cyclic transition state, the allylation reactions are highly regio- and stereospecific when homoallyl alcohols having a substituted allyl group are used. Whereas triarylphosphine is known to serve as a ligand for the palladium-catalyzed allyl transfer reactions, tricyclohexylphosphine proves to significantly expand the scopes of aryl halides to electron-rich
Photocatalytic Dehydroxymethylative Arylation by Synergistic Cerium and Nickel Catalysis
作者:Yuegang Chen、Xin Wang、Xu He、Qing An、Zhiwei Zuo
DOI:10.1021/jacs.1c00618
日期:2021.4.7
broad range of free alcohols and aromatichalides can be facilely employed in this transformation, representing a new paradigm for the C(sp3)–C(sp2) bond construction between free alcohols and aryl halides with the extrusion of formaldehyde. Moreover, mechanistic investigations have been conducted, leading to the identification of a tribenzoate cerium(III) complex as a viable intermediate.
The fluoride free cross-coupling between aryldimethylsilanes and organic halides proceeded in the presence of monocopper(i) alkoxide of ethylene glycol. The similar reaction of alkenyldimethylsilanes also took place with complete retention of configuration.
Thiourea–I2 as Lewis base–Lewis acid cooperative catalysts are developed for the iodochlorination of alkenes with in situ-generated iodinemonochloride (I–Cl). The Lewis base–Lewis acid cooperative system is sufficient to generate I–Cl from I2 with a chlorinating reagent at low temperature. Based on the solid-state structure of the active species, thiourea–I2 cooperatively captures I–Cl. By taking
硫脲-I 2作为路易斯碱-路易斯酸协同催化剂被开发用于用原位生成的一氯化碘(I-Cl)进行烯烃的碘氯化。刘易斯碱-路易斯酸协同体系足以在低温下用氯化剂从I 2生成I-Cl 。基于活性物质的固态结构,硫脲I 2协同捕获I Cl。通过利用I–Cl生成和在低温下控制I–Cl的优势,硫脲– I 2协同系统抑制了由高反应性游离I–Cl引起的副反应。