Summary
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]
| ZACA reaction | |||||||||||||||
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| Reaction type | transition metal catalyzed organometallic functionalization | ||||||||||||||
| Reaction | |||||||||||||||
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| Conditions | |||||||||||||||
| Typical solvents | typically DCM | ||||||||||||||
See also edit
References edit
- ^ Negishi, Ei-ichi (2010). "Discovery of ZACA reaction − Zr-catalyzed asymmetric carboalumination of alkenes". Arkivoc. 2011 (8). Arkat USA: 34-45. doi:10.3998/ark.5550190.0012.803. hdl:2027/spo.5550190.0012.803.
- ^ Denis Y. Kondakov; Ei-ichi Negishi (1995). "Zirconium-catalyzed enantioselective methylalumination of monosubstituted alkenes". J. Am. Chem. Soc. 117 (43): 10771–10772. doi:10.1021/ja00148a031.
- ^ Bo Liang (2007). Zirconium-catalyzed Asymmetric Carboalumination of Alkenes (ZACA reaction): Its development and application to the synthesis of deoxypolypropionates and other chiral compounds (Google Books excerpt) (Ph.D. thesis). Purdue University. p. 29. ISBN 978-0-549-50694-2.
- ^ Xu, Shiqing; Oda, Akimichi; Kamada, Hirofumi; Negishi, Ei-ichi (2014-06-10). "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. 111 (23). National Academy of Sciences: 8368–8373. doi:10.1073/pnas.1401187111. JSTOR 23776425. PMC 4060698. PMID 24912191.
- ^ Ze Tan; Bo Liang; Shouquan Huo; Ji-cheng Shi; Ei-ichi Negishi (2006). "Zirconium-catalyzed asymmetric carboalumination (ZACA reaction) of 1,4-dienes". Tetrahedron: Asymmetry. 17 (4): 512–515. doi:10.1016/j.tetasy.2006.01.017.