2024-03-29T05:14:45Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/453732022-11-17T02:08:08Zhdl_2115_20045hdl_2115_139Direct enantio-convergent transformation of racemic substrates without racemization or symmetrizationIto, HajimeKunii, ShunSawamura, Masayaopen access431Asymmetric reactions that transform racemic mixtures into enantio-enriched products are in high demand, however, classical kinetic resolution (KR) can afford enantiopure compounds in <50% yield even in an ideal case. Many deracemization processes thus have been developed including dynamic kinetic resolution (DKR) and dynamic kinetic asymmetric transformation (DYKAT), which can provide enantio-enriched products even after complete conversion of the racemic starting materials; however, these dynamic processes require racemization or symmetrization of the substrates or intermediates. We demonstrate a first chemical direct enantio-convergent transformation without racemization or symmetrization process. The copper(I)-catalysed asymmetric allylic substitution of a racemic allyl ethers afforded a single enantiomer of an α-chiral allylboronates with complete conversion and high enantioselectivity (up to 98% ee); one enantiomer of the substrate undergoes an anti-SN2'-type reaction whereas the other enantiomer reacts via a syn-SN2' pathway. The products, α-chiral allylboronates, cannot be prepared by dynamic procedures, were used in construction of all-carbon quaternary stereocentres.Nature Publishing Group2010-11engjournal articleAMhttp://hdl.handle.net/2115/45373https://doi.org/10.1038/NCHEM.801209669551755-4330Nature Chemistry211972976https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/45373/1/NC2-11_972-976.pdfapplication/pdf1.05 MB2010-11