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Iridium-Catalyzed Chemoselective and Enantioselective Hydrogenation of (1-Chloro-1-Alkenyl) Boronic Esters


  • We thank A. Vesković, S. Borišek, Dr. M. Črnugelj, S. Omovšek, D. Orkič, Dr. F. Nerozzi and Dr. D. Grainger for technical assistance in some experimental work, Dr. H. Nedden, Dr. D. Šterk, Dr. H.-U. Blaser, and Prof. A. Pfaltz for valuable discussions, P. Drnovšek for support, and P. Skelton (Univ. of Cambridge) for HRMS analysis.


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Persistent chlorine: Hydrogenation of borolane-substituted vinylic chlorides catalyzed by Ir[BOND]P N complexes greatly preserved the chlorine substituent on the hydrogenated product, with only 3–19 % of dechlorinated byproducts present after hydrogenation. The α-chloro boronic ester products are ideal precursors for proteasome-inhibitor-type anti-cancer drugs, a fact which demonstrates the utility of this hydrogenation method.