Chiral Diaryliodonium Phosphate Enables Light Driven Diastereoselective α‑C(sp3)–H Acetalization

• Published in: Journal of the American Chemical Society Vol. 140; no. 26; pp. 8350 - 8356
• Main Authors: Ye, Baihua, Zhao, Jie, Zhao, Ke, McKenna, Jeffrey M, Toste, F. Dean
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 05.07.2018; Amer Chemical Soc
• Subjects: Acetals - chemical synthesis; Acetals - chemistry; Chemistry; Chemistry, Multidisciplinary; Ethers, Cyclic - chemistry; Furans - chemistry; Light; Molecular Structure; Onium Compounds - chemistry; Phosphates - chemistry; Physical Sciences; Pyrans - chemistry; Science & Technology; Stereoisomerism; C(SP)-H BOND ACTIVATION; VISIBLE-LIGHT; ANION PHASE-TRANSFER; IODONIUM SALTS; ABSTRACTION REACTIONS; HYDROGEN-ATOM TRANSFER; ALIPHATIC-AMINES; SUBSTITUTED PHENYL RADICALS; C-H ACTIVATION; CATIONIC-POLYMERIZATION
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/jacs.8b05962

C­(sp3)–H bond functionalization has emerged as a robust tool enabling rapid construction of molecular complexity from simple building blocks, and the development of asymmetric versions of this reaction creates a powerful methodology to access enantiopure sp3-rich materials. Herein, we report the stereoselective functionalization of C­(sp3)–H bonds of cyclic ethers employing a photochemically active diaryliodonium salt in combination with an anionic phase-transfer catalyst. The synthetic strategy outlined herein allows for regio- and stereochemical control in the α-C–H acetalization of furans and pyrans using alcohol nucleophiles, thus providing the ability to control the configuration at the stereogenic exocyclic acetal carbon.