Design and Synthesis of C₄-Symmetric Axially Chiral β-Aryl Porphyrins and Application for Supporting Ir(III)-Catalyzed Enantioselective C-H Alkylation

Shanshan Yuan; Jun-Chao Sun; Xiao-Ming Zhao; Jieping Zhu; Sheng-Cai Zheng

doi:10.1002/anie.202404329

Design and Synthesis of C₄-Symmetric Axially Chiral β-Aryl Porphyrins and Application for Supporting Ir(III)-Catalyzed Enantioselective C-H Alkylation

Angew Chem Int Ed Engl. 2024 Apr 29:e202404329. doi: 10.1002/anie.202404329. Online ahead of print.

Authors

Shanshan Yuan¹, Jun-Chao Sun¹, Xiao-Ming Zhao¹, Jieping Zhu², Sheng-Cai Zheng³

Affiliations

¹ Tongji University, School of Chemical Science and Engineering, CHINA.
² EPFL Institute of Chemical Sciences and Engineering, Laboratory of Synthesis and Natural Products (LSPN), SWITZERLAND.
³ Tongji University, School of Chemical Science and Engineering, 1239 Siping Road, Shanghai, P. R. China., 200092, Shanghai, CHINA.

PMID: 38683742
DOI: 10.1002/anie.202404329

Abstract

A hitherto unknown class of C4-symmetric Caryl-Cβ (C3, C8, C13, C18) axially chiral porphyrins has been synthesized and the application of their iridium (Ir) complexes in catalytic asymmetric C(sp3)-H functionalization is documented. Cyclotetramerization of enantioenriched axially chiral 2-hydroxymethyl-3-naphthyl pyrroles under mild acidic conditions affords, after oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), the C4-symmetric α,α,α,α-atropenantiomer as an only isolable diastereomer. Both regioisomeric Ir(Por*)(CO)(Cl) complexes catalyze the carbene C-H insertion reaction affording the same enantiomer, albeit with slight difference in enantioselectivity. With the optimum Ir-complex 3e, the 2-substituted arylacetic acid derivatives were generated from diazo compounds and cyclohexadiene in excellent yields and enantioselectivities.

Keywords: Carbene Insertion; Iridium Complex; Porphyrin; asymmetric synthesis; axial chirality.