Metal-Free, Aerobic Dioxygenation of Alkenes Using Simple Hydroxamic Acid Derivatives

Abstract

The dioxygenation of alkenes using molecular oxygen and a simple hydroxamic acid derivative has been achieved. The reaction system consists of readily prepared methyl N-hydroxy-N-phenylcarbamate and molecular oxygen with a radical initiator, offering an alternative to common dioxygenation processes catalyzed by precious transition metals. This transformation capitalizes on the unique reactivity profile of hydroxamic acid derivatives in radical-mediated alkene addition processes.

Free‐Radical Multicomponent Processes

“…Further reduction of the N-O bond with Zn then furnishes the desired diol as depicted in Scheme 14.28 (1). Styrenes, dienes, enynes, cyclic olefins (norbornene), and electron-poor olefins such as methacrylates were shown to react with hydroxamic acid 122, under an oxygen atmosphere (1 atm) [84]. An initiation step produces the electrophilic amidoxyl radical that first adds onto the olefin, producing a new radical intermediate.…”

Fe(PyTACN)‐Catalyzed cis‐Dihydroxylation of Olefins with Hydrogen Peroxide

“…[1,2] cis-Dihydroxylation reactions are commonly performed with stoichiometric amounts of MnO 4 À , and heavy metal oxides such as RuO 4 and OsO 4 . [20][21][22][23][24][25][26] Towards this end, organic peroxides have been recently explored with promising results. Outstanding and predictable stereoselectivities and yields can be routinely attained by using well-established Cinchona alkaloid ligands.…”

Arylphosphonylation and Arylazidation of Activated Alkenes

“…Tosyl amide substrates that bear electrondonating or electron-withdrawing groups at the para position of the aromatic ring that is directly bound to the nitrogen atom (R 1 ; Table 2) produced the corresponding b-phosphonyl and b-azido amides 2 b-e and 3 b-e in good yields (entries [3][4][5][6][7][8][9][10]. Tosyl amide substrates that bear electrondonating or electron-withdrawing groups at the para position of the aromatic ring that is directly bound to the nitrogen atom (R 1 ; Table 2) produced the corresponding b-phosphonyl and b-azido amides 2 b-e and 3 b-e in good yields (entries [3][4][5][6][7][8][9][10].…”