Towards the 150th Anniversary of the Markovnikov Rule

The Markovnikov rule, known to every student of organic chemistry, was formulated 150 years ago, in 1869. During its long history (almost as long as the history of organic chemistry itself), attitudes towards this famous statement of chemical reactivity have evolved from indifference up to the 1930s, through common acceptance as a useful educational paradigm with marginal use in research up to the 1990s, to its vigorous relaunch as an important designation of regioselectivity in the last few decades. The unexpected new popularity of the classical rule is accounted for by the rapid expansion in catalytic addition reactions and their critical importance as highly effective atom‐economical, regioselective methods in modern organic synthesis. A historical outline of the life and achievements of Vladimir Markovnikov is included to reveal the very wide scope of his interests as well as his prophetic predictions on structure, reactivity, selectivity, stereochemistry, and other key issues of organic chemistry.     

Palladium‐Catalyzed Ring‐Forming Aminoalkenylation of Alkenes with Aldehydes Initiated by Intramolecular Aminopalladation

A palladium‐catalyzed aminopalladation reaction followed by nucleophilic addition with aldehydes and dehydration is described. This direct and operationally simple procedure provides a rapid and reliable approach to a wide range of functionalized tetrahydroisoquinolines with high selectivity. Mechanistic studies disclosed that the nucleophilic addition, performed via a highly ordered transition‐state, is the turnover‐limiting step in which the inherent β‐hydride elimination of the key Csp³−Pd species was controlled by the confined conformation and the nucleophilicity of the Csp³−Pd bond was enhanced by the strong electron‐donating effect of the nitrogen atom.