ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
1/1
0/0

Three-Component [1+1+1] Cyclopropanation with Ruthenium(II)

preprint
revised on 28.03.2018 and posted on 28.03.2018 by Tanner C. Jankins, Robert Fayzullin, Eugene Khaskin
We report a one-step, Ru(II)-catalyzed cyclopropanation reaction that is conceptually different from the previously reported protocols that include Corey-Chaykovsky, Simmons-Smith, and metal catalyzed carbene attack on olefins. Under the current protocol, various alcohols are transformed into sulfone substituted cyclopropanes with excellent isolated yields and diastereoselectivities. This new reaction forms highly congested cyclopropane products with three new C–C bonds, three or two new chiral centers and one new quaternary carbon center. 22 examples of isolated substrates are given. Previously reported synthetic routes for similar substrates are all multi-step, linear routes that proceed with overall low yields and poor control of stereochemistry. Experimental mechanistic investigations suggest initial metal-catalyzed dehydrogenation of the alcohol substrate and catalyst independent stepwise attack of two equivalents of sulfone on the aldehyde under basic conditions. While the Ru(II) is only responsible for the initial dehydrogenation step, the rate of aldehyde formation is crucial to maintaining the right balance of intermediates needed to afford the cyclopropane product.

History

Email Address of Submitting Author

eugenekhaskin@oist.jp

Email Address(es) for Other Author(s)

jankinst@scripps.edu robert.fayzullin@gmail.com

Institution

Okinawa Institute of Science and Technology

Country

Japan

ORCID For Submitting Author

0000-0003-1790-704X

Declaration of Conflict of Interest

No conflict of interest

Exports

Read the published paper

in Organometallics

Logo branding

Exports