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Pd-Catalyzed Regio- and Atroposelective Hydroalkynylation of Allene to Access Axially Chiral Conjugated 1,3-Enynes
Gen Li1, Xuechen Li1, Yi Yu1
1Department of Applied Chemistry, Anhui Province Engineering Laboratory for Green Pesticide Development and Application, and Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, 230036 Hefei, China.
Abstract:
The efficient synthesis of regio- and stereodefined multisubstituted conjugated 1,3-enynes, particularly those with axial chirality, remains challenging and underdeveloped. In this work, an efficient atroposelective hydroalkynylation of allene is established precisely synthesizing a broad range of conjugated 1,3-enynes containing a chiral C-N axis or C-C axis with high functional group tolerance (>80 examples), excellent atroposelectivity, regioselectivity, and E-selectivity. Notably, this strategy could provide atropisomers with up to three stereogenic axes with excellent enantioselectivity (up to 99% ee). The further transformation of the carbon-carbon triple bond enables efficient construction of various acyclic C-C or C-N axially chiral tetrasubstituted alkenes.
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