Stereoselective Halogenations

Abstract

Halogen‐containing bioactive molecules (organohalogens) are part of an interesting chemical space for biological investigation. To date, there are more than 4000 such molecules in nature, and they are implicated in biological responses like cytotoxicity toward cancer cell lines and seafood poisoning. This chapter will describe the more established stereoselective CX bond formation (CCl, CBr, and CI) leading to bioactive natural products or molecules containing chiral halogens. Experimental details of selected methods are also provided. In brief, the methods described herein are classified in three major classes, namely, substrate‐controlled methods, reagent‐controlled methods, and catalytic methods.

General Synthetic Approach for the Laurencia Family of Natural Products Empowered by a Potentially Biomimetic Ring Expansion

“…How such a process was effected mechanistically, however, was not described, with no demonstration, to the best of our knowledge, that simple chemical brominating sources could achieve a similar transformation from 9 in any yield since this original disclosure. Key, though, was that it established the likelihood that such a bromine atom was incorporated biosynthetically as an electrophile, not as a nucleophile as has been typical of the vast majority of the laboratory syntheses of family members; indeed, nearly every laboratory synthesis has installed such bromines via alcohol substitution chemistry. , …”