Jean-Francois Briere

Considering the challenge of sustainability facing our society in the coming decades, catalysis is without any doubt a research area of major importance. In this regard, asymmetric organocatalysis, now considered a pillar of green chemistry, deserves particular attention. The first chapter of this volume examines the topic of asymmetric organocatalysis in light of radical chemistry. Recent important progress in this field has been attained by promoting the formation and harnessing the high reactivity of open-shell intermediates. Merging organocatalysis with radical chemistry has been the key to solving some longstanding bottlenecks, and has also significantly contributed to reinforcing the key role of organocatalysis in asymmetric catalysis. This chapter presents the most significant developments in this area, with a particular focus on asymmetric SOMO- and photoredox-organocatalyzed transformations. Chapter 2 focuses on quaternary ammonium salts (R4N+X-), especially chiral derivatives, and their behavior as unique catalysts in organocatalysis. Forming chiral ion-pairs capable of promoting asymmetric reactions, they also operate as unique “transporters? involved in phase transfer catalytic processes between liquid–liquid or liquid–solid systems. Furthermore, they offer unique opportunities when forming cooperative ion-paired entities R4N+X-, allowing a synergistic implication of the counter-ion X- either as Brønsted bases or Lewis bases. Specific design of such chiral catalysts in modern chemistry and better insight into their mode of activation facilitates efficient and unprecedented chemical transformations. This chapter provides an overview of the use of chiral quaternary ammonium salts in organocatalysis, emphasizing both general mechanistic aspects and the scope of this approach.

Featuring a beautiful new design, THE EARTH AND ITS PEOPLES, Sixth Edition, presents world history in a balanced, global framework, shifting the focus away from political centers of power. This truly global text for the world history survey course employs fundamental themes of "environment and technology" and "diversity and dominance" to explore patterns of humans' interactions with their surroundings and with each other. The authors' approach reveals how humanity continues to shape and be shaped by the environment and how dominant structures and traditions are balanced and challenged by alternate beliefs. Special emphasis is given to technological development and how it underlies all human activity. Highly acclaimed in their fields of study, the authors bring a wide array of expertise to the program. A combination of strong scholarship and detailed pedagogy gives the book its reputation for rigor and student accessibility.

Regardless of your confidence level with French, BRAVO!, 8e is a proven solution for success! The book's unique approach enables you to review first-year structures independently before you learn to master new material. BRAVO!, 8e helps you expand your linguistic and cultural knowledge through readings, audio recordings, specialized vocabulary development, and concise yet thorough grammar explanations. A variety of carefully crafted activities-all designed to build competence and confidence in using spoken French in and out of the classroom-help you along the way.