Selective reactions between phenols and formaldehyde. A novel route to salicylaldehydes

Asymmetric Cyclopropanation of Styrene Catalyzed by Cu–(Chiral Schiff-Base) Complexes

“…Substituted salicylaldehydes were synthesized according to literature methods. [24][25][26] Optical rotations were measured on a SEPA-200 high sensitive polarimeter. NMR spectra were recorded on a Bruker DRX-400NMR spectrometer with tetramethyl silane as an (S)-2-Amino-1,1-di(2-n-butoxy-5-t-butylphenyl)propanol.…”

Synthesis and characterization of organotin Schiff base chelates

“…The reagent 3,5-di-tert -butyl-2-hydroxybenzaldehyde was prepared according to the literature [16]. Triethylamine, n-butyltin trichloride, and tin tetrachloride were purchased (Aldrich) and used as received.…”

Synthesis of salicylaldehydes from phenols via copper-mediated duff reaction

“…These methods possess their individual advantages, however, low ortho-selectivity of the most of these methods and poor yields sharply limited their application in industry [25]. Ortho-formylation of phenols by formaldehyde, POCl 3 /DMF or Cl 2 CHOMe in the presence of metal salts, such as Ag [25], Ti [26], and Sn [27] salts were reported. Despite the difficulty in preparation of intermediates and harsh conditions required, most of the methods were limited for the formylation of phenols bearing electron-withdrawing groups.…”