Synthesis of β-acetoxy alcohols by PhI(OAc)₂-mediated metal-free diastereoselective β-acetoxylation of alcohols

Abstract

β-Acetoxy alcohols can be synthesized in good yields with excellent diastereoselectivity from tertiary alcohols through PhI(OAc)2-mediated metal-free β-acetoxylation. Mechanistic studies showed that the β-acetoxylation process might undergo dehydration and sequential highly regioselective and diastereoseletive dioxygenation. Gram scale and diverse useful scaffolds could be prepared via this β-acetoxylation process.

Enroute sustainability: metal free C–H bond functionalisation

“…In 2016, the Su and Mo group performed a PIDA mediated β-acetoxylation of tertiary alcohol 161a for the synthesis of β-acetoxy alcohols 161b in good yield with excellent diastereoselectivity (Scheme 161). 206 This reaction afforded the best results in acetic acid solvent at 100–130 °C. The transformation was found to be good for diarylalkyl alcohol; however replacement of the aryl group by the alkyl group eventually decreased the yield and no transformation was observed for trialkyl alcohol.…”

Neighboring Carbonyl Group Assisted Oxyacetoxylation of Propargylic Carboxylates with Retention of Chirality under Metal Free Condition

“…When propargylic acetate 1 a was subjected to reaction without addition of water, the desired oxyacetoxylation product 2 a was obtained only in 12% yield even after heating the reaction mixture for 24 h, revealing the requirement of water for the oxyacetoxylation (Scheme A). Previous studies on alkyne functionalization supports that BAIB promotes alkyne oxidation via alkynyliodonium intermediate A . We sought to evaluate whether such an intermediate will facilitate the oxyacetoxylation process through the nucleophilic attack of the neighboring acetate group.…”

Synthesis of ω-Chloroalkyl Aryl Ketones via C–C Bond Cleavage of tert-Cycloalkanols with Tetramethylammonium Hypochlorite

“…Aqueous tetramethylammonium hypochlorite (TMAOCl) was prepared from aqueous tetramethylammonium hydroxide (TMAOH) by ion-exchange method (14.0 wt% TMAOCl, 7.86 wt% available chlorine, pH = 11.5) [36]. Compounds 1b [20], 1c [45], 1d-1g [20], 1h [46], 1i [47], 1j-1k [20], 1l [48], and 1m-1o [20] were synthesized according to the reported methods.…”