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Chiral Phosphine–Phosphite Ligands in Asymmetric Gold Catalysis: Highly Enantioselective Synthesis of Furo[3,4‐ d ]‐Tetrahydropyridazine Derivatives through [3+3]‐Cycloaddition
Author(s) -
Du Qingwei,
Neudörfl JörgMartin,
Schmalz HansGünther
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201800042
Subject(s) - phosphine , cycloaddition , enantioselective synthesis , furan , chemistry , catalysis , yield (engineering) , ligand (biochemistry) , combinatorial chemistry , tandem , medicinal chemistry , organic chemistry , materials science , biochemistry , receptor , metallurgy , composite material
The Au I ‐catalyzed reaction of 2‐(1‐alkynyl)‐2‐alken‐1‐ones with azomethine imines regio‐ and diastereoselectively affords furo[3,4‐d]tetrahydropyridazines in a tandem cyclization/intermolecular [3+3]‐cycloaddition process under mild conditions. By employing a chiral gold catalyst (prepared in situ from a Taddol‐derived phosphine‐phosphite ligand, Me 2 SAuCl, and AgOTf) high yields and enantioselectivities (up to 94 % yield, up to 96 % ee ) are obtained. The method provides an efficient modular route to substituted heterotricyclic furan derivatives and can be easily scaled up (using catalyst loads of only 0.15 mol %).