Electrochemically site-selective alkoxylation of twisted 2-arylbenzoic acids via spirolactonization

Abstract

The Electrochemical Cross-Dehydrogenative Coupling (ECDC) of twisted biphenyl-2-carboxylic acids with aliphatic alcohols provides 4`-alkoxyspirolactones which isomerize, under mild basic conditions, to give 4`-alkoxy-2-phenylbenzoic acids. This site-selective alkoxylation was readily adapted...

Electrochemical Dearomative Spirocyclization of N‐Acyl Sulfonamides in a Continuous‐Flow Cell†

“…[20][21][22] Compared with traditional chemical methods, electrochemical synthesis merits good selectivity control, mild reaction conditions, and prospect for sustainability. [23][24][25][26][27][28] While most electrochemical dearomative spirocyclizations are carried out in batch reactors, [29][30][31][32][33][34][35][36][37][38] there are relatively few cases of using electrochemical continuous-flow syntheses. [39][40][41][42] Compared with batch reactors, continuous-flow electrochemical microreactors are easy to scale up in short reaction time.…”

Electrochemical dearomative spirocyclization of N-acyl sulfona-mides in a continuous-flow cell

“…[18][19][20] Compared with traditional chemical methods, electrochemical synthesis merits good selectivity control, mild reaction conditions, and prospect for sustainability. [21][22][23][24][25][26] While most electrochemical dearomative spirocyclizations are carried out in batch reactors, [27][28][29][30][31][32][33][34][35][36] there are relatively few cases of using electrochemical continuous-flow syntheses. [37][38][39][40] Compared with batch reactors, continuous-flow electrochemical microreactors are easy to scale up in short reaction time.…”

Electrochemical Dearomative Spirocyclization

“…Using ortho ‐blocked biphenyl‐2‐carboxylic acids 105 , Gonzalez‐Gomez and co‐workers have synthesized a series of spirolactones 106 in the presence of fatty alcohols, resulting in the highly selective alkoxylation at the remote C‐4′ position of spironolactone (Scheme 25). [63] While acidic isomerization was not successful, the alkaline (KOH in EtOH) facilitated a quantitative isomerization. This electrochemical dehydrogenation cross‐coupling (ECDC)/isomerization procedure allowed the chiral substrate 105 a to be remotely functionalized while maintaining the original high enantiomeric ratio ( 107 a ).…”