Synfacts 2012; 8(3): 0279
DOI: 10.1055/s-0031-1290226
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Asymmetric Synthesis of Stable Oxetenes via [2+2] Cycloaddition

Contributor(s):
Mark Lautens
,
Hongqiang Liu
Aikawa K, Hioki Y, Shimizu N, Mikami K * Tokyo Institute of Technology, Japan
Catalytic Asymmetric Synthesis of Stable Oxetenes via Lewis Acid Promoted [2+2] Cycloaddition.

J. Am. Chem. Soc. 2011;
133: 20092-20095
Further Information

Publication History

Publication Date:
20 February 2012 (online)

 

Significance

The synthesis of stable oxetenes remains a challenging task due to the increased ring strain imposed by a double bond in the ring. Herein, the authors present the first highly enan­tioselective synthesis of stable oxetene derivatives via an atom-economical [2+2] cycloaddition of various alkynes with trifluoropyruvate using the chiral dicationic palladium complex 1 as an efficient Lewis acid catalyst.


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Comment

This method efficiently constructs stable oxetene derivatives bearing a CF3 group. The reactions proceed in excellent enantioselectivity and yields at up to 0.5 mmol scales with very low catalyst loading (0.1 mol%). The products can serve as novel chiral CF3 building blocks for pharmaceuticals and agrochemicals, and can be further converted into a variety of chiral CF3-containing compounds with excellent stereoselectivity.


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