Ferrocene—Beauty and Function

FerroceneBeauty and Function S ince ferrocene was independently discovered in 1951 by Kealy, Pauson, and Miller, the impact of this breakthrough and pioneering work has been enormous.It opened new areas of chemistry, deepened our understanding of structure, bonding, and reactivity, and hence paved the way for the burgeoning field of organometallic chemistry itself.Ferrocene and ferrocene-based molecules are not mere trophy molecules for the shelf; rather, the synthesis of this sandwich system in all its flavors, its versatile reaction chemistry, structural features, attendant mechanistic and theoretical studies, its use in homogeneous catalysis, especially in stereoselective and asymmetric transformations, in electrochemistry, particularly in electron-transfer processes, as new materials including polymer chemistry, as fuel additives, as anticancer reagents, in bioorganometallic chemistry, etc. has contributed to the rapid growth and hence rapidly moving frontiers of this family of compounds during the last 60+ years.The special issue FerroceneBeauty and Function highlights all of these topics and confirms the sustained key role of ferrocene in organometallic chemistry.The cover art for this issue is intended to convey the strong excitement and enthusiasm for ferrocene and ferrocene-based molecules of all the contributors of this special issue, although the number, quality, and diversity of the contributions are challenging to combine in a single artistic rendering.We tried, however, to graphically illustrate some major topics addressed in this issue.Synthetic advances in the field of ferrocene chemistry ranging from basic substitution reactions to stereoselective transformations and polymer synthesis are reported by several groups.A review article by Lang gives an overview of methodologies developed so far for the synthesis of planar chiral ferrocences.Gasser and co-workers report a threecomponent reaction of aminomethyl ferrocenes, amines, and elemental sulfur to give thioamides.Applying the ferrocene diamine scaffold to generate a chelating bis(phosphinoamide) ligand system has been shown by Fryzuk to effectively prevent ligand redistribution in scandium hydride complexes.Zakrzewski obtained monoalkenylated ferrocenes using electron-poor alkenes and Pd(OAc) 2 /4,5-diazafluoren-9-one as catalyst in an aerobic dehydrogenative Heck alkenylation of ferrocene.Butenschon discloses an anionic thia-Fries rearrangement of electron-rich ferrocenyl triflates to ferrocenoles.Half-open ferrocenes with edge-bridged open indenyl ligands are presented by Tamm and co-workers.Walter reports the synthesis, reactivity, and electronic structure of sterically encumbered diazaferrocenes.Jakle presents a new route to planar chiral Lewis acid base pairs by borylation of stannyl-(pyridyl) and mercurio(pyridyl) ferrocenes disclosing different (stereochemical) mechanisms.Tamm and co-workers provide the ferrocene community with an efficient and simple method for the preparation of 1,1′-ferrocenedicarboxylic acid and various 1,1′-disubstituted ferrocenes derived therefrom.AB and AB 2 block copolymers consisting of redox-active poly-(vinylferrocene) and biodegradable poly(L-lactide) have been crafted by Frey and Gallei.A diastereoselective ortho