Transition Metal-Catalyzed Directed C(sp3)–H Functionalization of Saturated Heterocycles

Synthetic methods that can readily access saturated heterocycles with different substitution patterns and with control of stereo- and regiochemistry are of huge potential value in the development of new medicinal compounds. Directed C-H functionalization of simple and commercially available precursors offers the potential to prepare diverse collections of such valuable compounds that can probe the different available exit vectors from a ring system. Nonetheless, the presence of the Lewis basic heteroatoms makes this a significant challenge. This review covers recent advances in the catalytic C-H functionalization of saturated heterocycles, with a view to different heterocycles (N, O, S), substitution patterns and transformations. 1 Introduction 2 alpha-C-H Functionalization with Directing Group on Nitrogen 3 C-H Functionalization at Unactivated C(3), C(4), and C(5) Positions 3.1 C-H Functionalization at C(3) with Directing Groups at C(2) 3.2 C-H Functionalization at C(3), C(4), and C(5): Directing Groups at C(4) and C(3) 4 Transannular C-H Functionalization 5 Conclusion