Iridium-Catalyzed Asymmetric Hydrogenation of Tetrasubstituted Exocyclic Olefins: An Efficient Access to Dexmethylphenidate

Iridium-catalyzed asymmetric hydrogenation of 5-hydroxypicolinate pyridinium salts under batch and flow: stereodefined access to cis-configurated hydroxypiperidine esters

“…We initiated our studies by employing the 2-benzyl ester-5hydroxypyridinium salt 1a as the model substrate. Extensive studies have shown that Ir complexes are extremely effective catalysts in the stereoselective hydrogenation of unsaturated nitrogenated compounds, [39][40][41][42][43] leading to high-value chiral amine scaffolds with high stereoselectivities. The initial reactions were conducted at a temperature of 25 °C in dichloromethane (DCM) as the solvent, with NaHCO 3 serving as the additive and [Ir(COD)Cl] 2 acting as the catalyst.…”

Enantioselective Palladium(II)‐Catalyzed Desymmetrizative Coupling of 7‐Azabenzonorbornadienes with Alkynylanilines

“…And the Wheeler's energy decomposition analysis (see details in Supporting Information, Figure S2) in Scheme 6b indicates that the energy difference between TS3 and TS4 could be attributed to the stabilizing interactions between substrate and catalyst in different transition states. [23] Structure analysis shows that two non-covalent interactions, the CH•••N [24] and CH•••π [25] interaction, could be observed in TS3, whereas only one CH•••π interaction is formed in TS4. These non-covalent interactions could be further confirmed by the NIC analysis (see Figure S2 in Supporting Information).…”

“…Various 7-azabenzonorbornadienes were then interrogated with different 2-alkynylanilines to further examine the feasibility and generality of this desymmetrization strategy (Scheme 3). Interestingly, this methodology is viable for polyfunctional azabenzonorbornadienes with diverse electronic properties and the introduction of methyl (24), methylenedioxy (25), ethylenedioxy (26) and fluoro group (27) could be well tolerated, furnishing the corresponding enantioenriched indole-dihydronaphthalene-amine skeletons 24-27 with excellent absolute stereocontrol (up to 95 % ee). Moreover, the protection group of the 7-azabenzonorbornadiene could also be varied as showcased by the preparation of compound 28 with a Ts group in 68 % yield with 96 % ee, motivating us to evaluate other N-protected azabenzonorbornadienes.…”