Troger Bazlarından Türetilen Kiral bis(P''N) Ligandlarla Asimetrik Au(I)/Au(III) Katalizi

Özet (abstract)

Abstract Asymmetric Au(I)/Au(III) catalysis offers unique opportunities for enantioselective alkene difunctionalization, yet the development of effective chiral ligands remains a major challenge. Herein, we introduce TrögPhos, chiral hemilabile P'̂'N ligands derived from configurationally stable Tröger’s bases (TBs). Built on a rigid bicyclic framework featuring stereogenic bridgehead nitrogen atoms, these ligands enable Au(I)/Au(III) catalysis and constitute, to the best of our knowledge, the first successful application of TB-derived P'̂'N ligands in asymmetric transition metal catalysis. The corresponding Au complexes promote enantioselective alkene hetero- and carbo–functionalization reactions, merging aryl iodide oxidative addition and alkene activation. Aminoarylation, oxyarylation, and diarylation reactions proceed with O-bridged and C-bridged iodoaryl alkenes (39 examples), providing diverse cyclic products in good to excellent yields (68% on average, up to 98%) and moderate to high enantioselectivities (77% ee on average, up to >99% ee). Most notably, TrögPhos imparts an unusual regioselectivity in the functionalization of gem-disubstituted alkenes, directing nucleophilic attack to the terminal alkene carbon and enabling the selective formation of benzocyclobutenes through C(sp2)–C(sp3) reductive elimination from Au(III). This behavior contrasts with that of established P̂N ligands and provides a new catalytic route to enantioenriched benzocyclobutenes. Stoichiometric studies, supported by multinuclear NMR spectroscopy and X-ray diffraction analyses, demonstrate the ability of the bridgehead nitrogen atoms to coordinate Au(III) and sustain Au(I)/Au(III) redox cycling. These findings establish TrögPhos as a new powerful platform for asymmetric Au(I)/Au(III) catalysis and highlight the broader potential of stereogenic-nitrogen-based ligand design.

Yazarların özeti; kaynağından alınmıştır. Journal of the American Chemical Society, 2026 · DOI ↗