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Showing 1 - 6 of 6 matches in All Departments
In 1972, a very powerful catalytic cycle for carbon-carbon bond formation was 2 first discovered by the coupling reaction of Grignard reagents at the sp -carbon. Over the past 30 years, the protocol has been substantially improved and expanded to other coupling reactions of Li, B, N, O, Al, Si, P, S, Cu, Mn, Zn, In, Sn, and Hg compounds. These reactions provided an indispensable and simple methodology for preparative organic chemists. Due to the simplicity and rel- bility in the carbon-carbon, carbon-heteroatom, and carbon-metalloid bo- formations, as well as high efficiency of the catalytic process, the reactions have been widely employed by organic chemists in various fields. Application of the protocol ranges from various syntheses of complex natural products to the preparation of biologically relevant molecules including drugs, and of sup- molecules, and to functional materials. The reactions on solid surfaces allow robot synthesis and combinatorial synthesis. Now, many organic chemists do not hesitate to use transition metal complexes for the transformation of org- ic molecules. Indeed, innumerable organic syntheses have been realized by the catalyzed reactions of transition metal complexes that are not achievable by t- ditional synthetic methods. Among these, the metal-catalyzed cross-coupling reactions have undoubtedly contributed greatly to the development of such a new area of "metal-catalyzed organic syntheses." An excellent monograph for the cross-coupling reactions and other met- catalyzed C-C bond-forming reactions recently appeared in Metal-catalyzed Cross-coupling Reactions (Wiley-VCH,19
Directed metalation is recognized as one of the most useful methodologies for the regio- and stereoselective generation of organometallic species, the generation of which necessarily leads to the selective formation of organic products. Cyclometalation using Li, Mn, and Pd, and directed hydrometalation and carbometalation using Al and Zn, have been utilized for regio- and/or stereoselective synthesis for decades. Recently, a new chelation-assisted methodology has been developed not only for controlling regio- and stereoselectivity of reactions, but also for accelerating reactions. In particular, chelation-methodology has been utilized as a new activation method, in which a carbon-metal bond is generated directly from a C-H bond; a reaction rarely achieved using conventional methods. A wide variety of catalytic functionalization reactions of C-H bonds by the utilization of a chelation, have been developed recently and are comprehensively discussed in this book by leading experts. In addition, new approaches to directed hydrometalation and directed carbometalation as a key step are also discussed. A unique stereo- and regioselective hydroformylation has been developed through the utilization of directed hydrometalation. The regioselective Mizoroki-Heck reaction is another example in which directed carbometalation can be used to achieve a high regioselectivity. These examples emphasize how these innovative methodologies are contributing to different fields of chemistry.
Directed metalation is recognized as one of the most useful methodologies for the regio- and stereoselective generation of organometallic species, the generation of which necessarily leads to the selective formation of organic products. Cyclometalation using Li, Mn, and Pd, and directed hydrometalation and carbometalation using Al and Zn, have been utilized for regio- and/or stereoselective synthesis for decades. Recently, a new chelation-assisted methodology has been developed not only for controlling regio- and stereoselectivity of reactions, but also for accelerating reactions. In particular, chelation-methodology has been utilized as a new activation method, in which a carbon-metal bond is generated directly from a C-H bond; a reaction rarely achieved using conventional methods. A wide variety of catalytic functionalization reactions of C-H bonds by the utilization of a chelation, have been developed recently and are comprehensively discussed in this book by leading experts. In addition, new approaches to directed hydrometalation and directed carbometalation as a key step are also discussed. A unique stereo- and regioselective hydroformylation has been developed through the utilization of directed hydrometalation. The regioselective Mizoroki-Heck reaction is another example in which directed carbometalation can be used to achieve a high regioselectivity. These examples emphasize how these innovative methodologies are contributing to different fields of chemistry.
In 1972, a very powerful catalytic cycle for carbon-carbon bond formation was 2 first discovered by the coupling reaction of Grignard reagents at the sp -carbon. Over the past 30 years, the protocol has been substantially improved and expanded to other coupling reactions of Li, B, N, O, Al, Si, P, S, Cu, Mn, Zn, In, Sn, and Hg compounds. These reactions provided an indispensable and simple methodology for preparative organic chemists. Due to the simplicity and rel- bility in the carbon-carbon, carbon-heteroatom, and carbon-metalloid bo- formations, as well as high efficiency of the catalytic process, the reactions have been widely employed by organic chemists in various fields. Application of the protocol ranges from various syntheses of complex natural products to the preparation of biologically relevant molecules including drugs, and of sup- molecules, and to functional materials. The reactions on solid surfaces allow robot synthesis and combinatorial synthesis. Now, many organic chemists do not hesitate to use transition metal complexes for the transformation of org- ic molecules. Indeed, innumerable organic syntheses have been realized by the catalyzed reactions of transition metal complexes that are not achievable by t- ditional synthetic methods. Among these, the metal-catalyzed cross-coupling reactions have undoubtedly contributed greatly to the development of such a new area of "metal-catalyzed organic syntheses." An excellent monograph for the cross-coupling reactions and other met- catalyzed C-C bond-forming reactions recently appeared in Metal-catalyzed Cross-coupling Reactions (Wiley-VCH,19
Proceedings of the NSF Research Workshop on Contact Transformations, Held in Nashville, Tennessee, 1974
What did it mean to be happy in early modern Europe? Positive emotions in early modern literature and culture includes essays that reframe historical understandings of emotional life in the Renaissance, focusing on under-studied feelings such as mirth, solidarity, and tranquillity. Methodologically diverse and interdisciplinary, these essays draw from the history of emotions, affect theory and the contemporary social and cognitive sciences to reveal rich and sustained cultural attention in the early modern period to these positive feelings. The book also highlights culturally distinct negotiations of the problematic binary between what constitutes positive and negative emotions. A comprehensive introduction and afterword open multiple paths for research into the histories of good feeling and their significances for understanding present constructions of happiness and wellbeing. -- .
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