Catalytic cascade reactions by radical relay

Abstract

Catalytic radical relays are an attractive tool for the rapid construction of complex molecular architectures.

Trifluoromethyl radical triggered radical cyclization of N-benzoyl ynamides leading to isoindolinones

“…We thus pursued our optimization study with Ir(ppy) 3 and showed that Umemoto reagent was not very competent in this reaction compared to Togni I & II reagents (entry 5 vs. entries 3 & 6). Solvent screening confirmed that acetonitrile was the best (entry 3 vs. entries [7][8][9][10]. Reactions with Togni II generally showed the presence of minor carboxylate adducts 5a and 6a (approximately 5-8% of 5a and 3% of 6a detected by HPLC) resulting from the carboxylation of the ynamide moiety and a double addition of the radical CF (Scheme 3) [41,42].…”

“…Inter-and intramolecular radical addition -cyclization tandems constitute a powerful method to assemble various scaffolds depending on the used partners [1][2][3][4][5][6][7][8][9]. For instance, this approach has been applied by using a trifluoromethyl radical as a trigger [10][11][12] to synthesize valuable fluorine containing substrates [13][14][15][16].…”

Advances in Asymmetric Amino Acid Synthesis Enabled by Radical Chemistry

“…[60][61][62][63][64][65][66] Moreover, owing to the generally mild reaction conditions and often high functional group tolerance, radical chemistry represents a well-suited strategy for chemoselective modifications of peptides and proteins. [61][62][63][64][65][66] In general, radical approach [67][68][69][70][71][72] is widely applied in the field of organic synthesis for the rapid construction of complex molecular architectures [73][74][75] and the total synthesis of natural products under safe and mild conditions. [76][77][78][79][80][81] Even in nature many of oxidation processes catalyzed by heme proteins and metalloporphyrins have proceeded through a radical mechanism.…”

Direct Enamido C(sp2)−H Diphosphorylation Enabled by a PCET‐Triggered Double Radical Relay: Access to gem‐Bisphosphonates

“…[13] Herein, we report am ajor advance for synthesizing geminal bisphosphonates by means of silver-mediated direct 1,1-diphosphorylationo fe namides (Scheme 1c). [14] By taking advantage of proton-coupled electron transfer (PCET) [15] -triggered radicalr elay process, [16] this study implementedt he first example of two-fold CÀPb ond formation from C(sp 2 )ÀHb ond at a same carbon atom. [17] More importantly,t his reactiona llows the efficient synthesis of ab road range of fully functionalized b-aminov inyl gem-BPs, as well as halogen,a zirine, ketone, peptide, and alkyne-substituted ones, thus considerably opening up new possibilities in expanding the potentialc hemical space in this emerging field.…”