Zhou HQ, Gu XW, Zhou XH, Li L, Ye F, Yin GW, Xu Z, Xu LW. Enantioselective palladium-catalyzed C(sp
2)-C(sp
2) σ bond activation of cyclopropenones by merging desymmetrization and (3 + 2) spiroannulation with cyclic 1,3-diketones.
Chem Sci 2021;
12:13737-13743. [PMID:
34760158 PMCID:
PMC8549799 DOI:
10.1039/d1sc04558j]
[Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 09/19/2021] [Indexed: 11/21/2022] Open
Abstract
Catalytic asymmetric variants for functional group transformations based on carbon–carbon bond activation still remain elusive. Herein we present an unprecedented palladium-catalyzed (3 + 2) spiro-annulation merging C(sp2)–C(sp2) σ bond activation and click desymmetrization to form synthetically versatile and value-added oxaspiro products. The operationally straightforward and enantioselective palladium-catalyzed atom-economic annulation process exploits a TADDOL-derived bulky P-ligand bearing a large cavity to control enantioselective spiro-annulation that converts cyclopropenones and cyclic 1,3-diketones into chiral oxaspiro cyclopentenone–lactone scaffolds with good diastereo- and enantio-selectivity. The click-like reaction is a successful methodology with a facile construction of two vicinal carbon quaternary stereocenters and can be used to deliver additional stereocenters during late-state functionalization for the synthesis of highly functionalized or more complex molecules.
An unprecedented palladium-catalyzed (3 + 2) spiro-annulation merging C–C bond activation and desymmetrization was developed for the enantioselective construction of synthetically versatile and value-added oxaspiro products with up to 95% ee.![]()
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