Electrochemically Enabled Carbohydroxylation of Alkenes with H₂O and Organotrifluoroborates

Abstract

Unprecedented hydroxy-alkynylation and -alkenylation reactions of arylalkenes have been developed through electrochemically enabled addition of an organotrifluoroborate reagent and H 2 O across the double bond of the alkene. The use of electrochemistry to promote these oxidative alkene 1,2-difunctionalization reactions not only obviates the need for transition-metal catalysts and oxidizing reagents but also ensures high regio-and chemoselectivity to afford homopropargylic or homoallylic alcohols. The possibility of extending the electrochemical alkene difunctionalization strategy to other alkene carbo-heterofunctionalization reactions has been demonstrated.

Hexafluoro‐2‐Propanol‐Promoted Electro‐Oxidative [3+2] Annulation of 1,3‐Dicarbonyl Compounds and Alkenes

“…Electrosynthesis, which can avoid the external oxidants by employing the electrons to achieve the redox reaction, is considered as a versatile and eco‐friendly synthetic strategy and has experienced remarkable renaissance in recent years . The electrochemical alkene difunctionalization is emerging as a approach to construct C−C, C−N, C−O, C−Cl and so on . We envisioned acyclic 1,3‐dicarbonyl compounds, which has interested the chemists over the years due to the high oxidation potential of acyclic 1,3‐dicarbonyl compounds, might serve as C‐radical sources and nucleophilic oxygen sources to react with alkenes, achieving the electro‐oxidative [3+2] annulation with hydrogen evolution.…”

“…The electrochemical alkene difunctionalization is emerging as a approach to construct CÀ C, CÀ N, CÀ O, CÀ Cl and so on. [41][42][43][44][45][46][47][48][49][50][51][52] We envisioned acyclic 1,3-dicarbonyl compounds, which has interested the chemists over the years due to the high oxidation potential of acyclic 1,3-dicarbonyl compounds, might serve as C-radical sources and nucleophilic oxygen sources to react with alkenes, achieving the electro-oxidative [3 + 2] annulation with hydrogen evolution. However, there are few reports about the carbon-centered radicals generated through the direct cleavage of the acidic α-CÀ H of the 1,3-dicarbonyl compounds by using electricity instead of transition metals or oxidants.…”

Recent Advances in Electrochemical Oxidative Cross‐Coupling of Alkenes with H2 Evolution

“…Electron‐rich olefins could be oxidized directly to achieve bifunctional reactions. In 2018, Xu and co‐workers developed electrochemical carbohydroxylation of alkenes with H 2 O and organotrifluoroborates (Scheme ) . Alkynyl‐ and alkenyltrifluoroborate salts were used as alkenylation or alkynylation reagent in this electrochemical system efficiently.…”

“…In 2018, Xu and co-workers developed electrochemical carbohydroxylation of alkenes with H 2 O and organotrifluoroborates (Scheme 16). [23] Alkynyl-and alkenyltrifluoroborate salts were used as alkenylation or alkynylation reagent in this electrochemical system efficiently. In addition, this reaction could also be expanded to gram scale.…”

Facilitating Gold Redox Catalysis with Electrochemistry: An Efficient Chemical‐Oxidant‐Free Approach

“…[7] In particular, electrochemical anodic oxidation is more attractive since it serves as an environmentally friendly and sustainable alternative oxidation strategy. [8] Recent works have demonstrated its capability to promote the challenging oxidation of transition-metal cations to their higher oxidation states,s uch as Pd II/IV or Co I/II/III oxidation. [9] Another advantage of electrochemical oxidation is the controllable cell potential (E cell ), which allows fine-tuning of transition-metal redox processes for optimal reactivity.C onsidering these advantages,w es et out to explore the possibility of achieving gold redox catalysis under electrochemical conditions to overcome the high oxidation potential between Au I and Au III .H erein, we report the first example of electrochemical gold redox catalysis that dose not require any external oxidant (Scheme 1B).…”