Intercepting fleeting cyclic allenes with asymmetric nickel catalysis

Michael M. Yamano, Andrew V. Kelleghan, Qianzhen Shao, Maude Giroud, Bryan J. Simmons, Bo Li, Shuming Chen, K. N. Houk () and Neil K. Garg ()
Additional contact information
Michael M. Yamano: University of California, Los Angeles
Andrew V. Kelleghan: University of California, Los Angeles
Qianzhen Shao: University of California, Los Angeles
Maude Giroud: University of California, Los Angeles
Bryan J. Simmons: University of California, Los Angeles
Bo Li: University of California, Los Angeles
Shuming Chen: University of California, Los Angeles
K. N. Houk: University of California, Los Angeles
Neil K. Garg: University of California, Los Angeles

Nature, 2020, vol. 586, issue 7828, 242-247

Abstract: Abstract Strained cyclic organic molecules, such as arynes, cyclic alkynes and cyclic allenes, have intrigued chemists for more than a century with their unusual structures and high chemical reactivity1. The considerable ring strain (30–50 kilocalories per mole)2,3 that characterizes these transient intermediates imparts high reactivity in many reactions, including cycloadditions and nucleophilic trappings, often generating structurally complex products4. Although strategies to control absolute stereochemistry in these reactions have been reported using stoichiometric chiral reagents5,6, catalytic asymmetric variants to generate enantioenriched products have remained difficult to achieve. Here we report the interception of racemic cyclic allene intermediates in a catalytic asymmetric reaction and provide evidence for two distinct mechanisms that control absolute stereochemistry in such transformations: kinetic differentiation of allene enantiomers and desymmetrization of intermediate π-allylnickel complexes. Computational studies implicate a catalytic mechanism involving initial kinetic differentiation of the cyclic allene enantiomers through stereoselective olefin insertion, loss of the resultant stereochemical information, and subsequent introduction of absolute stereochemistry through desymmetrization of an intermediate π-allylnickel complex. These results reveal reactivity that is available to cyclic allenes beyond the traditional cycloadditions and nucleophilic trappings previously reported, thus expanding the types of product accessible from this class of intermediates. Additionally, our computational studies suggest two potential strategies for stereocontrol in reactions of cyclic allenes. Combined, these results lay the foundation for the development of catalytic asymmetric reactions involving these classically avoided strained intermediates.

Date: 2020
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41586-020-2701-2 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:586:y:2020:i:7828:d:10.1038_s41586-020-2701-2

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/s41586-020-2701-2

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().