R. B. Woodward: A Larger-than-Life Chemistry Rock Star

The Ways of Science Through the Lens of the Woodward-Hoffmann Rules. The Stories Begin*

This is Paper 1 in a 27-paper series on the history of the development of the Woodward-Hoffmann rules, also known as the Principle of Conservation of Orbital Symmetry. In addition to presenting an outline of this series, this manuscript provides a short overview of the chemical problem eventually solved by the Woodward-Hoffmann rules is presented.

On the Structural Assignments Underlying R. B. Woodward's Most Personal Data That Led to the Woodward-Hoffmann Rules: Subramania Ranganathan's Key Role and Related Research by E. J. Corey and A. G. Hortmann

In the early 1960s, as part of R. B. Woodward's isoxazole route to vitamin B₁₂ , Subramania Ranganathan uncovered two coupled sets of stereospecific reactions, a thermal set and a photochemical set. These four reactions illustrated the alternating configurations that were the major data points that prompted the solution of the no-mechanism problem. Though Ranganathan's reactions played a major role, according to Woodward, in the development of the Woodward-Hoffmann rules, they were published only as part of the documentation of a lecture given by Woodward in 1966. The authors of this paper have uncovered Subramania Ranganathan's 1964 postdoctoral report and have used modern quantum chemical theory to predict the ¹ H NMR spectra for Ranganathan's key compounds, providing support for the structure assignments made by Woodward and Ranganathan. A similar set of alternating, stereospecific reactions was observed by E. J. Corey and Alfred Hortmann in their 1963 total synthesis of dihydrocostunolide. We also have applied the computational process used for Ranganathan's compounds to Hortmann's compounds, now also including the calculation of coupling constants, and find computational support for Corey and Hortmann's structure assignments.

Classic highlights in porphyrin and porphyrinoid total synthesis and biosynthesis

Porphyrins feature prominently in nature, be it as enzymatic cofactors, electron and exciton shuffles, as photoactive dyes, or as signaling substances. Their involvement in the generation, storage and use of oxygen is pivotal to life, while their photochemical properties are central to the biochemical functioning of plants. When complexed to metals, porphyrins can engage in a multitude of contemporary applications ranging from solar energy generation to serving as catalysts for important chemical reactions. They are also able to function as useful theranostic agents, and as novel materials for a wide range of applications. As such, they are widely considered to be highly valuable molecules, and it almost goes without saying that synthetic organic chemistry has dramatically underpinned all the key advances made, by providing reliable access to them. In fact, strategies for the synthesis of functionalized porphyrins have now reached a state of refinement where pretty well any desired porphyrin can successfully be synthesized with the approaches that are available, including a cornucopia of related macrocycle-modified porphyrinoids. In this review, we are going to illustrate the development of this exciting field by discussing a number of classic syntheses of porphyrins. Our coverage will encompass the natural protoporphyrins and chlorophylls, while also covering general strategies for the synthesis of unsymmetrical porphyrins and chlorins. Various industrial syntheses of porphyrins will also be discussed, as will other routes of great practical importance, and avenues to key porphyrinoids with modified macrocycles. A range of selected examples of contemporary functionalization reactions will be highlighted. The various key syntheses will be described and analyzed from a traditional mechanistic organic chemistry perspective to help student readers, and those who are new to this area. The aim will be to allow readers to mechanistically appreciate and understand how many of these fascinating ring-systems are built and further functionalized.

The Relationship of William Henry Perkin, Jr. and Sir Robert Robinson: Teacher and Student, then Student and Teacher

William Henry Perkin, Jr. FRS, the son of the inventor of mauve and other commercial dyes and credited for initiating the industrialization of chemistry, was himself a notable chemist. He was the Professor of Organic Chemistry at Manchester from 1892-1912 and then was the Waynflete Professor of Chemistry at Oxford and the first Head of the Dyson Perrins Laboratory from 1912-1929. One of Perkin's graduate students and research assistants at Manchester was Robert Robinson, subsequently Sir Robert Robinson, FRS and recipient of the 1947 Nobel Prize in Chemistry. Perkin and Robinson had perhaps the most productive and broad collaboration between a professor and one's student. Together, during and after Robinson's student days, they had 71 joint publications, 25 of which involved just the two of them, 17 of which involved the structure determination of strychnine, and eight of which were published after Perkin's death in 1929. Upon Perkin's early death, Robinson succeeded him as the fourth Waynflete Professor of Chemistry at the Dyson Perrins Laboratory, Oxford University. This Essay will examine the professional relationship of Perkin, Jr. and Robinson as revealed in their joint publications on the structure of strychnine.

The strategies and techniques of drug discovery from natural products

Natural products have been the main sources of new drugs. The different strategies have been developed to find the new drugs based on natural products. The traditional and ethic medicines have provided information on the therapeutic effects and resulted in some notable drug discovery of natural products. The special activities of the medicine plants such as the side effects have inspired scientists to develop the novel small molecular. The microorganisms and the endogenous active substances from human or animal also become the important approaches to the drug discovery. The tremendous progress in technology led to the new strategies in drug discovery from natural products. The bioinformation and artificial intelligence have facilitated the research and development of natural products. We will provide a scene of strategies and technologies for drug discovery from natural products in this review.