Exploration of Halogen Bonding for the Catalysis of Organic Reactions

Iodine-induced catalysis, started more than a hundred years ago, has considerably progressed by now. Environmental compatibility, easy availability, and versatile activity makes it a good alternative to transition-metal-based Lewis acids. However, the lack of possible structural modifications requires the development of new organic halogen-based Lewis acids with tailored properties. The high directionality of the halogen bond, the flexibility of utilizing different backbone scaffolds, and the availability of at least two different interacting atoms in different oxidation states makes it more promising than its much related noncovalent analog – hydrogen bonding. Started as a laboratory curiosity, the field is expanding now with a variety of new examples continuously emerging. Here, we provide a conceptual overview of all our efforts toward the utilization of this important interaction in the catalysis of organic transformations.