Desilylation‐Activated Propargylic Transformation: Enantioselective Copper‐Catalyzed [3+2] Cycloaddition of Propargylic Esters with β‐Naphthol or Phenol Derivatives

Abstract

Acopper-catalyzed asymmetric [3+ +2] cycloaddition of 3-trimethylsilylpropargylic esters with either b-naphthols or electron-rich phenols has been realized and proceeds by ad esilylation-activated process.U nder the catalysis of Cu-(OAc) 2 ·H 2 Oi nc ombination with as tructurally optimized ketimine P, N,N-ligand, aw ide range of optically active 1,2dihydronaphtho[2,1-b]furansor2,3-dihydrobenzofurans were obtained in good yields and with high enantioselectivities (up to 96 %e e). This represents the first desilylation-activated catalytic asymmetric propargylic transformation.

Enantioselective Copper‐Catalyzed Propargylic Etherification of Propargylic Esters with Phenols Promoted by Inorganic Base Additives

“…Given our recent success in the use of a chiral tridentate P,N,N‐ligand for the copper‐catalyzed asymmetric propargylic transformation,,–,– we envisioned that this ligand type could also provide a powerful solution to the copper‐catalyzed asymmetric propargylic etherification of propargylic esters, in particular aromatic propargylic esters. As a result, herein we report a highly enantioselective and efficient copper‐catalyzed propargylic etherification of both aromatic and aliphatic propargylic esters with phenols as oxygen nucleophiles.…”

Aerobic Oxidative Cleavage and Esterification of C(OH)–C Bonds

“…Esters are commonly used in different fields. [22][23][24][25] Among various types of esters, methyl esters exhibit unique biological activities and have been widely employed in the synthesis of pharmaceuticals 26,27 and polymers. 28,29 In the context of developing future biorefineries, selective esterification of C(OH)-C bonds is a very attractive option in terms of producing value-added chemicals from renewable resources, but it has not been reported so far.…”

Transformation of alcohols to esters promoted by hydrogen bonds using oxygen as the oxidant under metal-free conditions

“…Esters are used as important building blocks for the synthesis of bulk and commodity chemicals having wide applications in pharmaceuticals, polymers, solvents, fragrances, etc. (1)(2)(3). In practice, esters are generally synthesized via multistep processes involving the reaction between alcohols and acids or activated acid derivatives (for example, acid chlorides or anhydrides) (1).…”