A Claim on the Development of the Frontier Orbital Explanation of Electrocyclic Reactions

An important discovery took place in the period 1964-1969-it was the elaboration of the complex of ideas known variously as "the conservation of orbital symmetry" or "orbital symmetry control." The stereochemistry and ease (or difficulty) of the elementary steps of many organic reactions found an explanation in the phase relationships of their molecular orbitals. It was my fortune to collaborate with R. B. Woodward in this story. Our published work consisted of a series of five communications to the Editor of J. Am. Chem. Soc. in 1965, [1] a paper in Accounts of Chemical Research, [2] and, importantly, a final exposition of the ideas in an article of some length in Angewandte Chemie. [3] Woodward and I used a variety of theoretical approaches in our workfrom simple frontier orbital (HOMO/ LUMO) arguments, through orbital correlation diagrams, interaction diagrams, and perturbation theory arguments, to detailed molecular orbital calculations. There were good reasons not to use a single approach-symmetry was a way in to the solution, but its unthinking use would have imprisoned us. Still, there was a leitmotif in our work: orbitals and their symmetries mattered, and so did the number of electrons. Woodward and I were lucky-we not only rationalized a large, piecewise puzzling, body of chemistry, but also were able to make predictions that were verifiable by a community eminently capable and interested in probing experimentally the consequences of the theory. Orbital symmetry considerations were expeditiously tested; they were found to be portable and productive. The 1981 Nobel Prize in chemistry was awarded to Kenichi Fukui and me for this work; had R. B. Woodward lived, there isnt the least doubt that he would have shared in this recognition. Nature.Cover.jpg......Page 0 25 November 2004......Page 1 432421.pdf......Page 5 432423.pdf......Page 6 432424.pdf......Page 7 432425.pdf......Page 8 432426.pdf......Page 9 432427.pdf......Page 10 432428.pdf......Page 11 432432.pdf......Page 13 432439.pdf......Page 19 432441.pdf......Page 20 432443.pdf......Page 22 432444.pdf......Page 23 432447.pdf......Page 25 432449.pdf......Page 26 432450.pdf......Page 27 432454.pdf......Page 31 432456.pdf......Page 33 432458.pdf......Page 35 432459.pdf......Page 36 432460.pdf......Page 37 432460-1.pdf......Page 38 432461.pdf......Page 40 432466.pdf......Page 45 432473.pdf......Page 52 432479.pdf......Page 58 432482.pdf......Page 61 432486.pdf......Page 65 432488.pdf......Page 67 432492.pdf......Page 71 432502.pdf......Page 81 432508.pdf......Page 87 432512.pdf......Page 91 432517.pdf......Page 96 432522.pdf......Page 101 432526.pdf......Page 105 nj7016-531.pdf......Page 110 nj7016-532.pdf......Page 111