Advances in Heterocyclic Chemistry, Vol. 43

(from preface)Volume 43 of Advances in Heterocyclic Chemistry is composed of six chapters by an international set of authors. David Hewitt (Australia) provides us with the first available comprehensive review of heterocyclic six-membered rings containing phosphorus and nitrogen as heteroatoms: the azophosphorins.Chapters 2 and 3, both authored by Wilhelm Flitsch (Federal Republic of Germany), deal, respectively, with the chemistry of the azaazulenes (not previously covered since 1958) and of hydrogenated porphyrins, a class of increasing importance in biochemical processes. The reactivity of ring-nitrogen atoms in azines toward electrophiles is covered by M. R. Grimmett (New Zealand) and B. R. T. Keene (England) in Chapter 4.The longest chapter of this volume, authored by Roger Gallo and Christian Roussel (France) and Ulf Berg (Sweden), gives a comprehensive account of the quantitative treatment of steric effects in hcteroaromatic compounds—a subject that has been advanced significantly by these authors. Finally, V. N. Charushin and O. N. Chupakhin (USSR) and H. С van der Plas (The Netherlands) review reactions of azines with bifunctional nucleophiles.