Rhodaelectro‐Catalyzed peri‐Selective Direct Alkenylations with Weak O‐Coordination Enabled by the Hydrogen Evolution Reaction (HER)

Abstract

Direct CÀ H functionalizations by electrocatalysis is dominated by strongly coordinating N(sp 2 )directing groups. In sharp contrast, direct electrocatalytic transformations of weakly-coordinating phenols remain underdeveloped. Herein, electrooxidative peri CÀ H alkenylations of challenging 1-naphthols were achieved by versatile rhodium(III) catalysis via userfriendly constant current electrolysis. The rhodaelectrocatalysis employed readily-available alkenes and a protic reaction medium and features ample scope, good functional group tolerance and high site-and stereoselectivity. The strategy was successfully applied to high-value, nitrogen-containing heterocycles, thereby providing direct access to uncommon heterocyclic motifs based on the dihydropyranoquinoline skeleton.

Non-directed Pd-catalysed electrooxidative olefination of arenes

“…Based on these results and literature precedence, 23 a plausible Pd( ii / iv )-catalytic cycle is proposed for the electro-oxidative olefination of simple arenes (Scheme 4). The catalytic cycle starts with the anodic oxidation of the Pd( ii ) catalyst A to form a Pd( iii ) intermediate B. Arene C (sp 2 )–H bond activation delivers the organopalladium complex C which is converted to the Pd( iv ) species D by anodic oxidation.…”

“…According to an electrochemical study on approximate ranges of standard redox potentials for Pd intermediates in catalytic reactions, the oxidation of Pd( ii ) to Pd( iv ) is usually observed in the range of +1.00–2.00 V ( vs. Fc/Fc + = ferrocene) or 1.63–2.63 V ( vs. NHE). 23 The CV profile of Pd(OAc) 2 in the negative scan revealed two reduction waves at −0.23 V and at −1.06 V vs. NHE (Fig. S6†) which might refer to the redox conversion of Pd( ii / i ) and Pd( i /0).…”

“…1a) which might refer to the redox conversion of Pd( ii / iii ) and Pd( iii / iv ). 23 Fig. 1b shows the CVs of naphthalene (substrate), ligand L1 , n -butyl acrylate, and Pd(OAc) 2 .…”

Electrifying synthesis of organosilicon compounds – from electrosynthesis to electrocatalysis

“…Looking at organic chemistry we notice a tremendous growth of interest in the development of novel electrochemical methodologies. Ackermann, [1][2][3][4] Baran, [5][6][7][8] Lin, 9,10 Mei, [11][12][13] Waldvogel [14][15][16] and many other eminent scientists have proverbially brought electrosynthesis/electrocatalysis to light by turning it into a perfectly working synthetic tool. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] This, in turn, has many implications for the development of materials chemistry.…”

Electrochemical Amidation: Benzoyl Hydrazine/Carbazate and Amine as Coupling Partners

“…13 Thus, the proficiency of reactions can be greatly improved. In this context, Lei, 14 Lin, 15 Baran, 16 Ackermann, 17 and others 18 independently developed various electrochemical methods for the construction of C−C, C−X, and X−X (X = N, P, O, and S) bonds. Inspired by the electrochemical synthesis and the propensity of benzoyl hydrazine as an acyl radical and amine as the N-centered radical, herein, we report an electrochemical amide bond formation (Scheme 1d).…”