Synfacts 2017; 13(07): 0707
DOI: 10.1055/s-0036-1590600
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Dynamic Kinetic Resolution Approach: Synthesis of Axially Chiral Biaryls

Contributor(s):
Mark Lautens
,
Nicolas Zeidan
Yao Q.-J. Zhang S. Zhan B.-B. Shi B.-F. * Nankai University, Tianjin, and Zhejiang University, Hangzhou, P. R. of China
Atroposelective Synthesis of Axially Chiral Biaryls by Palladium-Catalyzed Asymmetric C–H Olefination Enabled by a Transient Chiral Auxiliary.

Angew. Chem. Int. Ed. 2017;
56: 6617-6621
Further Information

Publication History

Publication Date:
19 June 2017 (online)

 

Significance

Shi and co-workers report a protocol to access axially chiral biaryl systems by dynamic kinetic resolution. The approach relies on using tert-leucine as an inexpensive chiral auxiliary to allow selective C–H insertion into the favored atropisomer. Rotation is locked by a terminating Heck reaction.


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Comment

The products are delivered in excellent yields and enantioselectivity. The reaction displays great scalability and is performed on up to 5 mmol. Additionally, both enantiomers can be accessed by simply using the amino acid of opposite chirality. The authors found that if the substrates are substituted at both the 6- and 2′-positions, the reaction does not exhibit dynamic reversibility and hence a maximum of 50% yield can be achieved in such cases.


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