The development of new strategies for the functionalization of the historically inert C—H bond arises as an excellent way to create new carbon—carbon and carbon— heteroatom bonds. With increasingly chemo- and site-selective methods that enables the late-stage functionalization of C—H bonds, the modification of specific sites in natural products and pharmaceuticals without altering their scaffold emerges as a powerful means for the diversification of complex molecules. In this review, we will introduce concepts of late-stage modifications, the use of C—H bond functionalization to forge new carbon—carbon and carbon—heteroatom bonds using metal catalysis and photochemistry in simple examples and their applications in natural products and pharmaceuticals. The aim of the review is to update and display to the reader the contributions and implications of this methodology to organic synthesis. CH C H carboncarbon carbon chemo siteselective site selective latestage late stage molecules modifications carbonheteroatom synthesis

MOLECULAR SYMMETRY AND DESYMMETRIZATION REACTIONS IN ORGANIC SYNTHESIS. Molecular Symmetry has found several applications in Organic Chemistry. The aim of this article is to showcase its relevance as a tool for synthetic planning. Natural Products and synthetic compounds with pharmaceutical applications were selected to highlight desymmetrization reactions that make use of organocatalysis, biocatalysis or by transition metals. The recognition of structural patterns in retrosynthetic analysis is discussed for compounds that exhibit explicit or hidden symmetry. Limitations of the aforementioned strategies are also described, as well as the untapped potential, challenges and frontiers yet to be explored regarding these concepts.