1,721,000 research outputs found
Arene‐Ruthenium(II)‐Carboxylate für C–H‐Alkylierungen und Arylierungen bei Annährend Raumtemperatur
No full textDeutsche Forschungsgemeinschaft https://doi.org/10.13039/501100001659China Scholarship Council https://doi.org/10.13039/50110000454
Arene Ruthenium(II) Carboxylates for C─H Alkylations and Arylations at Near Room Temperature
No full textAbstract The long‐term pursuit for more efficient catalysts has stimulated the development of C─H activations under mild reaction conditions, with the overarching goal to improve their user‐friendly nature, selectivity, and synthetic utility. Herein, we report mild C─H alkylations enabled by inexpensive and most user‐friendly ruthenium carboxylate complexes. While these bench‐stable arene ruthenium carboxylate complexes catalyzed direct alkylations under ambient conditions, detailed kinetic studies demonstrated a high catalytic performance for the [Ru(O 2 CR) 2 ( p ‐cymene)] during the steady‐state catalytic process. Thus, temperature‐dependent kinetic Arrenhius‐plot analyses of the ruthenium‐catalyzed C─H alkylation revealed a comparable activation enthalpy for [Ru(O 2 CR) 2 ( p ‐cymene)] and [Ru( t‐ BuCN) 5 (H 2 O)](BF 4 ) 2 , hence, implying entropic factors to be of relevance. The robust arene ruthenium(II) carboxylate‐catalyzed C─H alkylation showed broad versatility under mild reaction conditions with respect to primary, secondary as well as tertiary alkyl bromides in a position‐divergent manner, reflecting a wide tolerance of valuable electrophilic functional groups for late‐stage functionalizations.Deutsche Forschungsgemeinschaft https://doi.org/10.13039/50110000165
‐Alkyl Sulfonamides in Aqueous Medium
No full textAbstract The construction of C−N bonds by free radical reactions represents a powerful synthetic approach for direct C−H amidations of arenes or heteroarenes. Developing efficient and more environmentally friendly synthetic methods for C−H amidation reactions remains highly desirable. Herein, metal‐free electrochemical oxidative dehydrogenative C−H amidations of heteroarenes with N‐alkylsulfonamides have been accomplished. The catalyst‐ and chemical‐oxidant‐free C−H amidation features an ample scope and employs electricity as the green and sole oxidant. A variety of heteroarenes, including indoles, pyrroles, benzofuran and benzothiophene, thereby underwent this C(sp2)−H nitrogenation. Cyclic voltammetry studies and control experiments provided evidence for nitrogen‐centered radicals being directly generated under metal‐free electrocatalysis.Heterocycles: Metal‐free electrochemical dehydrogenative C−H amidation of heteroarenes with N‐alkylsulfonamides have been accomplished. The catalyst‐ and chemical oxidant‐free C−H amidation featured ample substrate scope and employed electricity as the sole oxidant (see scheme). imageDFG http://dx.doi.org/10.13039/501100001659National Natural Science Foundation of China http://dx.doi.org/10.13039/50110000180
‐Koordination ermöglicht durch die Wasserstoffbildungsreaktion (HER)
No full textFundacja na rzecz Nauki Polskiej https://doi.org/10.13039/501100001870European Research Council https://doi.org/10.13039/501100000781Narodowa Agencja Wymiany Akademickiej https://doi.org/10.13039/501100014434China Scholarship Council https://doi.org/10.13039/50110000454
Site-selective electrochemical carboxylation of aromatic C(sp2)–H bonds with CO2
No full textOpen-Access-Publikationsfonds 202
Elektrooxidative Rhodium‐katalysierte [5+2]‐Anellierung durch C‐H/O‐H‐Aktivierung
No full textDFG http://dx.doi.org/10.13039/501100001659Alexander von Humboldt-Stiftung http://dx.doi.org/10.13039/100005156China Sponsorship Council (CN
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