For organic chemists (in training), the question of how to determine whether a chemical reaction follows the S_N2 or E2 route is timeless. A group in Amsterdam summarized its 25 years of research in Chemistry: A European Journal, offering concrete, simple concepts to overcome this dilemma.

Organic chemistry has its challenges. Where does a molecule attack? Does a molecule react as a base or a nucleophile? Does a reaction proceed via E1, S_N1, or S_N2? Of course, there’s also the question of the competition between S_N2 vs. E2 reactions. Thomas Hansen and Pascal Vermeeren, assistant professors at Free University Amsterdam, began researching the latter topic five to six years ago as part of their Ph.D. studies. The publications resulting from their work are now summarized in this Concept article.