Not all radicals are born equal! Some of them are going to make pretty smart decisions from an energy perspective, while others are a little on the crazy side. Let’s turn to some potential role models for guidance on this topic.
Concept #1: Radical selectivity: Alcoholics Anonymous Version
Selectivity is defined as the ability to only halogenate the carbons with most stable radical intermediates.
Predict the product of the following Radical Halogenation. Would the following reaction be synthetically useful? (Yielding only one product).
Example #1: Predict the product of the following Radical Halogenation. Would the following reaction be synthetically useful? (Yielding only one product).
Predict the product of the following Radical Halogenation. Would the following reaction be synthetically useful? (Yielding only one product).
Example #2: Predict the product of the following Radical Halogenation. Would the following reaction be synthetically useful? (Yielding only one product).
Predict the product of the following Radical Halogenation. Would the following reaction be synthetically useful? (Yielding only one product).
Example #3: Predict the product of the following Radical Halogenation. Would the following reaction be synthetically useful? (Yielding only one product).
Predict the product of the following Radical Halogenation. Would the following reaction be synthetically useful? (Yielding only one product).
Example #4: Predict the product of the following Radical Halogenation. Would the following reaction be synthetically useful? (Yielding only one product).
Early transition states could care less what they look like, whereas late transition states have to be much more careful about the arrangements they take.
Concept #2: Using the Hammond Postulate to describe radical chlorination.
Concept #3: Using the Hammond Postulate to describe radical bromination.