The ability to achieve any goals in our society is largely dependent upon, and limited by, the state-of-the-art tools available. While the speed and ease of the construction of large objects, such as buildings, are rapidly enhanced by the creation of various heavy machines, established fundamental chemical reactions, in combination with our creative and intelligent designing skills, ultimately determine the synthesis of chemical products.

The development of novel chemical reactivities and reaction conditions that can improve resource efficiency, energy efficiency, product selectivity, operational simplicity, as well as environmental health and safety, represents both an ideology and an aspiration for generations of synthetic chemists, more so than ever at this time. Ever since the synthesis of urea by Friedrich Wöhler in 1828, organic chemistry has become increasingly important in modern society. The invention of organic reactions over the past two centuries has allowed us to create synthetic organic compounds and materials that have now touched essentially every corner of our life: from cosmetics to fashion, from pharmaceuticals to agrochemicals, from transportation to the interior of skyscrapers, and from electronics to genetic modification. However, the archetypical requirements of standard classical chemical transformations are the functional groups, which provide the platform for chemical conversions that have led to the synthesis of millions of both naturally existing and non-naturally existing molecules in just less than two centuries, only a blinking moment in human history. In spite of the great successes, there are still various shortcomings: the pre-functionalized starting materials need to be synthesized in separate steps, and the amount of waste associated with solvent usage, purification and isolation maneuvers, as well as the required manpower to perform a synthesis increases exponentially with the number of synthetic steps. With recent concerns regarding the adverse effects of chemical production processes, as well as the emphasis on green chemistry and chemical sustainability, various frontiers of synthetic chemistry have been explored. Among them, the concept of the cross-dehydrogenative-coupling (CDC) reaction was formulated in 2003. The direct generation of a C–C bond from two different C–H bonds constitutes an ideal that has game-changing potential in synthetic design. The subject has become a very rapidly expanding field. This edited book will cover some of the key developments in this area.

Chao-Jun Li

Montreal, Canada