Catalyzed M–C coupling reactions in the synthesis of σ-(pyridylethynyl)dicarbonylcyclopentadienyliron complexes

Abstract

Two approaches were developed for the synthesis of iron σ-pyridylethynyl complexes based on Pd/Cu- and Pd-catalyzed Fe–C coupling reactions.

Reactions of a Gallane(pyridyl)iron Complex with Internal and Terminal Alkynyl Esters: C−O and C−C Bond Cleavage and Oxidative Addition of C−H Bond

“…X‐ray crystal structure analysis (Figure 1) revealed that complex 5 b possesses a three‐legged piano stool structure with two CO and η 1 ‐alkynyl ligands. The Fe−C3 (1.906(3) Å) and C3≡C4 (1.208(4) Å) bond distances are comparable to those of Fe−C single bonds (1.90‐1.93 Å) and C≡C triple bonds (1.17–1.21 Å) in Cp’(OC) 2 Fe(C≡C−R) complexes (R=H, Ph, and pyridyl, Cp’=Cp* and Cp) [13,18c,22] . The short C3−C4 bond distance and the linear Fe−C3−C4 and C3−C4−C5 bond angles (179.8(3)° and 177.0(3)°, respectively) indicate the sp ‐hybridization of the C3 and C4 atoms.…”

Pd/Cu-Catalyzed Coupling of Cyclopentadienyliron Dicarbonyl Iodide and Methyl Propiolate in Synthesis of Cp(CO)₂Fe-C≡C-COOMe

“…Третью, желто-коричневую фракцию элюировали смесью петролейный эфирэтилацетат (3:7), из которой после удаления растворителя было получено 248 мг (0,954 ммоль, 92 %) желто-коричневого порошка комплекса Cp(CO) 2 Fe-C≡C-COOMe (1).1 H ЯМР(CDCl 3 , 25 °С) δ, м.д. : 3,68 (с, 3H, -CH 3 ); 5,09 (с, 5H, C 5 H 5 ) 13. C NMR (CDCl 3 , 25 °С) δ, м.д.…”