| Popis: |
Transition metal-catalyzed C-H activation of heterocycles is a rapidly growing field in modern organic synthesis. The ubiquitous nature of C-H bonds and coordinating properties of heteroatoms makes this type of chemistry extra challenging in regard to regioselectivity. In this chapter, an overview is given about the latest trends in C-H activation on heterocycles as well as how regioselectivity could be obtained. The use of directing moieties is one outcome in the regioselectivity enigma, but this requires extra synthetic steps thereby having an adverse impact on the overall greenness of the transformation. Cross-dehydrogenative couplings are the most interesting class in direct functionalizations as they make use of two nonpreactivated substrates. Site-selectivity on both substrates, however, is an even bigger hurdle to take and competitive homocoupling needs to be avoided. |
