Catalytic asymmetric synthesis of planar-chiral transition-metal complexes

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

“…You presented an efficient Pd-catalyzed enantioselective intramolecular C-H activation of ferrocene with (R a )-BINAP as the source of chirality, [42] and some Ir, Rh, and Pd catalyses have been reviewed lately. [43,44] While in most cases noble second-or third-row transition metals were employed as the catalysts, Ackermann was the first one to report a cobaltcatalyzed C-H functionalization reaction at ferrocene, presenting the ortho-alkenylation of 2-ferrocenylpyridine (1) with 1cyclohexenyl acetate in 48 % yield with CoI 2 as the catalyst. [45] This sp 2 -sp 2 coupling is so far the only example of a cobaltcatalyzed C-H activation of ferrocene, though rapid progress has been achieved on arenes with low-and high-valent cobalt complexes.…”

Central (S) to Central (M=Ir, Rh) to Planar (Metallocene, M=Fe, Ru) Chirality Transfer Using Sulfoxide‐Substituted Mesoionic Carbene Ligands: Synthesis of Bimetallic Planar Chiral Metallocenes

“…Scheme8.Stereodivergent synthesis of enantiopure planarchiral bimetallic ruthenacycles 12 and 13.S electedb ond lengths []and angles [8]f or 12: IrÀC1 2.013(4), IrÀC15 2.066(4),Ir ÀCl 2.425(1),C1 ÀC2 1.383 (6), C2ÀN3 1.371(5), N1ÀN2 1.322(5), N2ÀN3 1.319(5), N1ÀC1 1.386 (5), N1ÀC111.421(7), N3ÀC3 1.462 (6), C2ÀS1 .763(4), SÀO1.489(4), SÀC4 1.787 (5), C1-Ir-C15 78.0(2), C1-Ir-Cl 85.7(1), C15-Ir-Cl 94.0(2). Selectedb ond lengths []and angles [8]f or 13:Ir ÀC1 2.021(5), IrÀC12 2.061(4),Ir ÀCl 2.424(2),C1 ÀC2 1.390(7), C2ÀN3 1.364 (6), N1ÀN2 1.323(5), N2ÀN3 1.329(5), N1ÀC1 1.376 (6), N1ÀC111.414(7), N3ÀC3 1.457 (6), C2ÀS1 .774 (5), SÀO1 .485(5), SÀC4 1.792 (5), C1-Ir-C12 78.3(2), C1-Ir-Cl8 4.3(2), C12-Ir-Cl 84.9(2). Finally,w es ubmitted complexes 5a and 6a to the CÀHa ctivation reactioni nd euterated 1,2-dichloroethane.…”

“…[7] Thus, methods for introducing planar chirality into ferrocene-derived compoundsh ave been widely investigated. [8] Planar chiralf errocenes are prepared mainly by the diastereoselective ortho-lithiation of ferrocenes having chiral directing groups, followed by reaction with electrophiles. The resulting products retain the additional element of symmetry.A lternatively, the enantioselective lithiation of ferrocene with chiral basesa nd the subsequenti ntroduction of an electrophile have been extensively used (Scheme 1).…”

Advances in Enantioselective C–H Activation/Mizoroki-Heck Reaction and Suzuki Reaction

“…It is well known that planar chiral ferrocenes are frequently applied as highly efficient catalysts or ligands in asymmetric synthesis [66][67][68][69][70][71]. Inspired by previous studies from Yu group [44,62], You et al, developed an enantioselective syntheses of planar chiral ferrocenes via palladium-catalyzed direct coupling with arylboronic acids in 2013 (Scheme 15) [72].…”