Pentynol to furan conversion – Search for the best trans-[MX2(YNC10H14O)2] catalyst

Cu(I) camphor coordination polymers: Synthesis and study of the catalytic activity for cyclization of 4‐pentyn‐1‐oic acid

“…One of the molecules of A cyclizes, forming the O −heterocycle (lactone) while the other one adds to the cycle through the carboxylic acid leaving a pendant alkyne group ( C , Scheme ). Related processes were found in the syntheses of furan or pyran type species from alkynols catalyzed by Pt(II) or Pd(II) camphor complexes showing that camphor complexes are prone to promote such type of processes. To exclude that the active species in the cyclization of A are CuCl, CuCl 2 (due to complexes decomposition) or the free camphor ligands, the reaction of each one of them with A was done separately and the mixture analyzed.…”

“…For calculation of the constants, the unitary activity was considered as 1/100 th of the integration of the NMR signal in the spectra obtained upon 4 min reaction, normalized to the number of magnetic nuclei. A FORTRAN subroutine was used to perform the numerical integration of the complete set of equations in Scheme 2 (using steps of 0.01 min). The output was then fed to a least squares routine and the generated values were optimized till convergence to experimental values was 0.992 ( 2 ; T = 40 °C), 0.999 ( 2 ; T = 60 °C) and 0.962 ( 3 ; global fitting of 2 loadings).…”

“…A step forward in the synthesis of camphor derived Cu(I) coordination polymers was to build copper polymers with two, rather than one CuCl strings, linked by the convenient camphor derivatives aiming at studying their properties as catalysts, a field where coordination polymers are high promising . Cyclization processes seemed promising since Pd(II) and Pt(II) camphor complexes were found to be high active in the cyclization of alkynes or alkynols and there is a current interest on efficient catalysts that promote the cyclization of functionalized alkynes alkynols or alkyne carboxylic acids within cyclization processes that encompass purely organic or metal mediated methodologies. Catalysts developed up to now are based on expensive transition metals (Pd, Pt, Au, or Ag) and require strong basic conditions.…”

Intramolecular Charge Transfer in Ruthenium Complexes [Ru(acac)2(ciq)] with Ambidentate Camphoriminoquinone (ciq) Ligands

“…[9,10] Some coordination compounds of N-organocamphoriminoquinone (ciq) ligands have been investigated structurally [10,11] and with respect to potentially catalytic properties. [10][11][12] In the present report we describe the results from reactions of the π accepting N-phenylcamphoriminoquinone (pciq, Figure 1) and of the o-thiomethyl-modified analogue N-(2thiomethylphenyl)-camphoriminoquinone (tciq) with strongly π donating {Ru(acac) 2 }, acac À = 2,4-pentanedionate. [13] Thiomethyl substituents have been used in noninnocent hemilabile benzenoid ligands [14][15][16] whose structure (coordination) and spin-spin coupling pattern depend on the redox state of the metal complexes.…”

“…[17] Monoimines as those in Figures 1 and 2 were used in connection with catalysis or biological activity. [10][11][12]…”