ZACA reaction explained

The zirconium-catalyzed asymmetric carbo-alumination reaction (or ZACA reaction) was developed by Nobel laureate Ei-ichi Negishi.^[1] It facilitates the chiral functionalization of alkenes using organoaluminium compounds under the influence of chiral bis-indenylzirconium catalysts (e.g. bearing chiral terpene residues,^[2] as in (+)- or (−)-bis[(1-neomenthyl)indenyl]zirconium dichloride^{[3] [4]}). In a first step the alkene inserts into an Al-C bond of the reagent, forming a new chiral organoaluminium compound in which the aluminium atom occupies the lesser hindered position. This intermediate is usually oxidized by oxygen to form the corresponding chiral alcohol (cf. hydroboration–oxidation reaction). The reaction can also be applied to dienes, where the least sterically hindered double bond is attacked selectively.^[5]

See also

• Organoaluminium chemistry
• Organozirconium chemistry
• Indenyl effect

Notes and References

1. Negishi . Ei-ichi . Ei-ichi Negishi . Arkivoc . Discovery of ZACA reaction − Zr-catalyzed asymmetric carboalumination of alkenes . 2010 . 2011 . 8 . 34-45 . 10.3998/ark.5550190.0012.803 . Arkat USA. free . 2027/spo.5550190.0012.803 . free .
2. Denis Y. Kondakov . Ei-ichi Negishi . Ei-ichi Negishi . Zirconium-catalyzed enantioselective methylalumination of monosubstituted alkenes . . 1995 . 117 . 43 . 10771–10772 . 10.1021/ja00148a031.
3. Ph.D. . Bo Liang . Zirconium-catalyzed Asymmetric Carboalumination of Alkenes (ZACA reaction): Its development and application to the synthesis of deoxypolypropionates and other chiral compounds. 29 . Google Books excerpt . Purdue University . 2007 . 978-0-549-50694-2 .
4. Xu . Shiqing . Oda . Akimichi . Kamada . Hirofumi . Negishi . Ei-ichi . Ei-ichi Negishi . Highly enantioselective synthesis of γ-, δ-, and ε-chiral 1-alkanols via Zr-catalyzed asymmetric carboalumination of alkenes (ZACA)–Cu- or Pd-catalyzed cross-coupling . Proceedings of the National Academy of Sciences of the United States . 2014-06-10 . 111 . 23 . 8368–8373 . 10.1073/pnas.1401187111 . National Academy of Sciences . 23776425 . 24912191 . 4060698 . free .
5. Ze Tan . Bo Liang . Shouquan Huo . Ji-cheng Shi . Ei-ichi Negishi . Ei-ichi Negishi . Zirconium-catalyzed asymmetric carboalumination (ZACA reaction) of 1,4-dienes . Tetrahedron: Asymmetry . 17 . 4 . 2006 . 512–515 . 10.1016/j.tetasy.2006.01.017.