Cyclopalladated complex of 1-ferrocenylisoquinoline

Cobalt‐Catalyzed ortho‐Methylation of Ferrocenes Bearing ortho‐Directing Groups by Catalytic Directed C–H Bond Activation

“…Bipyridyl and both sterically hindered (mesityl, SIMes) or more flexible (isopropyl, SIiPr) NHC ligands [10] (Entries 10-12) gave only traces or poor yields of rac-2, indicating that a diamine ligand is superior. We improved the synthesis of 1-ferrocenylisoquinoline (4) [57,58] with an increased yield of 44 % by generation of lithioferrocene from ferrocene instead of bromoferrocene and extended stirring (20 h) instead of workup with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone after 30 min. We improved the synthesis of 1-ferrocenylisoquinoline (4) [57,58] with an increased yield of 44 % by generation of lithioferrocene from ferrocene instead of bromoferrocene and extended stirring (20 h) instead of workup with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone after 30 min.…”

“…Shibata [57] introduced the 1-isoquinolyl group as an ODG resulting in a high yield of a racemic monoalkenylated ferrocene by an iridium-catalyzed alkenylation with only a small amount of the dialkenylated side product, presumably because of the steric bulk of this ODG. We improved the synthesis of 1-ferrocenylisoquinoline (4) [57,58] with an increased yield of 44 % by generation of lithioferrocene from ferrocene instead of bromoferrocene and extended stirring (20 h) instead of workup with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone after 30 min. When 4 was tested in the methylation reaction with Co(acac) 2 as the catalyst under the usual reaction conditions a high yield of 76 % of monomethylated rac-5 was obtained in addition to only 3 % of the achiral dimethylation product 6 (Scheme 1).…”

“…Org. [57,58] Ferrocene (1.77 g, 9.5 mmol) and potassium tert-butoxide (0.11 g, 1.0 mmol) were placed in a Schlenk tube and dissolved in THF (150 mL). 2017, 3041-3048 www.eurjoc.org © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 3045 0.1 mol L -1 ) was added.…”

“…Chem. Column chromatography (40 × 5 cm; petroleum ether/ethyl acetate, 9:1) afforded 4 (1.32 g, 4.2 mmol, 44 %) as a red oil, which was identified spectroscopically ( 1 H NMR [57,58] ). The reference electrode was an Ag/Ag + (AgNO 3 ) electrode in acetonitrile with 0.01 mol L -1 AgNO 3 and 0.1 mol L -1 of TBAP.…”

“…Then the reaction mixture was heated at reflux for 16 h. After cooling to 25°C, the reaction was quenched with water (50 mL [47] ). [57,58] Ferrocene (1.77 g, 9.5 mmol) and potassium tert-butoxide (0.11 g, 1.0 mmol) were placed in a Schlenk tube and dissolved in THF (150 mL). The solution was cooled to -78°C.…”