Cobalt-Catalysed Bond Formation Reactions; Part 2

Abstract

This review summarises the cobalt-catalysed reactions of the years 2008 through 2014. Covered are addition reactions, such as the hydrogenation of double bonds, the addition of C-H bonds to double and triple bonds, C-H activation reactions, cobalt-catalysed cross-coupling reactions and selected additions of H-B and H-Si bonds to unsaturated starting materials. The cobalt-catalysed cycloadditions range from cyclopropanations, [2+2], Pauson-Khand reactions, [2+2+2], [4+2], [6+2] cycloadditions as well as benzannulations. Also covered are Nicholas reactions, cobalt-catalysed Jacobsen's kinetic resolution of epoxides as well as selected miscellaneous cobalt-catalysed processes mainly for carbon-carbon bond formations. 1 Introduction 2 Addition Reactions 3 Homo-and Cross-Coupling Reactions 4 Jacobsen Kinetic Resolution of Epoxides 5 Nicholas Reactions 6 Cycloaddition Reactions 7 Miscellaneous 8 Conclusion

Intramolecular Nicholas Reactions in the Synthesis of Heteroenediynes Fused to Indole, Triazole, and Isocoumarin

“…Electrophile-promoted cyclization , and CuAAC of 1-iodoacetylenes , being applied to diacetylenes , with subsequent Sonogashira coupling , have been suggested as key steps for the construction of acyclic enediyne systems. The Nicholas reaction was chosen for the final macrocyclization step as a unique synthetic tool for the construction of various cyclic alkyne derivatives including natural enediynes and their analogues. − …”

Unpredictable cycloisomerization of 1,11-dien-6-ynes by a common cobalt catalyst

“…Over the last decade the application of the cobalt catalytic system CoBr 2 /phosphine ligand/Zn/ZnI 2 for the carbon–carbon bond formation has become a subject of a growing interest (for reviews see [15–21]). This catalytic system has many advantages, including the availability of the cobalt salts and high tolerance to organic functional groups (for some recent examples see [22–27]).…”