The quantitative electrophilic reactivity of annulenes. Part 2. Partial rate factors for hydrogen exchange of azulene, cycl[3,2,2]azine, indolizine, N-methylisoindole, indole, and pyrrolo[2,1-b]thiazole, and attempted exchange in trans-9,10-dimethyldihydropyrene: the dramatic effect of creating aromaticity in the transition state for electrophilic substitution, and the importance of valence bond theory

Abstract

118ChemInform Abstract On the basis of experimentally determined rates of acid-catalyzed detritiations of molecules such as (I)-(VI) together with some literature data on deuteration partial rate factors, σ+ values, reactivities, and reactive sites of the molecules considered are stimated. Further molecules under consideration are e.g. azaindolizines and the title compound (VII).

Design of an Indolylphosphine Ligand for Reductive Elimination-Demanding Monoarylation of Acetone Using Aryl Chlorides

“…We were intrigued to investigate the reductive elimination-demanding process by considering these two factors independently in a single ligand. To tackle the reductive elimination electronically, our rational design of ligand focuses on the less electron-rich phosphorus donor, for instance the −PPh 2 group (Figure ), where this group attached to the C3-indole position would enjoy essentially sufficient electron-richness for oxidative addition of the C (Ar) –Cl bond but also can facilitate the reductive elimination (i.e., too electron-rich phosphines, e.g., Ar-PCy 2 or Ar-P- t -Bu 2 , would slow the RE process) . In addition to studying the electronic nature of the phosphorus donor, we wanted to prepare a ligand with large remote bulky groups for promoting reductive elimination (Figure ).…”