0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via
19.6 Conclusions

DOI: 10.1055/sos-SD-240-00196

Faisca Phillips, A. M.; Guedes da Silva, M. F. C.; Pombeiro, A. J. L.Science of Synthesis: Cross-Dehydrogenative Coupling, (20231617.

Cross-dehydrogenative coupling has become a fertile area of chemical research in this century. Most of the interest in this subject stems from the fact that it is a highly environmentally friendly way to do synthesis, which bypasses the need for substrate derivatization prior to CH coupling, produces minimal waste, because the only byproduct is water, and is economical and time-saving. Many enantioselective cross-dehydrogenative coupling methods of synthesis have been developed so far, but the progress is still slow in comparison with the large number of papers published in this field every year. The harshness of some of the oxidants used or the high temperatures required initially were not very compatible with the chiral catalysts and ligands used. Nevertheless, the latest trends are toward mild conditions, with reactions often taking place at room temperature, and in many cases molecular oxygen or even air suffice as oxidants. Earth-abundant and relatively nontoxic metals, i.e. copper, iron, and cobalt, are being used more and more. Just like amines, simple ethers can now also be used as coupling partners in enantioselective reactions, which was not possible less than six years ago. Not only can chirality be introduced at newly formed C(sp3) centers, but axial chirality can also be created for biaryl synthesis and even planar-chiral ferrocenes can be obtained. Cooperative/synergistic new approaches utilizing organocatalysts, photoredox catalysts, and also electrochemical catalysis are being developed, widening the scope of cross-dehydrogenative coupling. Cascade reactions leading to the formation of more than one chiral center in a single synthetic operation are becoming more popular. On the whole, cross-dehydrogenative coupling is expected to remain a fertile field for the development of sustainable, environmentally friendly methods for the production of chiral substances in the years to come.