Iron‐Catalyzed Direct Diazidation for a Broad Range of Olefins

Abstract

Reported herein is a new iron-catalyzed diastereo-selective olefin diazidation reaction which occurs at room temperature (1-5 mol % of catalysts and d.r. values of up to > 20:1). This method tolerates a broad range of both unfunctionalized and highly functionalized olefins, including those that are incompatible with existing methods. It also provides a convenient approach to vicinal primary diamines as well as other synthetically valuable nitrogen-containing building blocks which are difficult to obtain with alternative methods. Preliminary mechanistic studies suggest that the reaction may proceed through a new mechanistic pathway in which both Lewis acid activation and iron-enabled redox-catalysis are crucial for selective azido-group transfer.

Electrochemical Azidooxygenation of Alkenes Mediated by a TEMPO–N3 Charge-Transfer Complex

“…Alternatively, in pathway 2b, TEMPO–N 3 directly delivers the N 3 group onto the alkene in a manner akin to metal-mediated radical group transfer. 37 This process results in the formation of TEMPO • and carbon-centered radical II , which subsequently cross couple to furnish the desired product. Finally, in pathway 2c, TEMPO–N 3 first decomposes into TEMPO • and azidyl radical (N 3 • ), upon which the sequential addition of these two open-shell species across the alkene yields the desired azidooxygenated product.…”

Late Stage Azidation of Complex Molecules

“…26,37,38 Recently developed methods include nucleophilic substitution reactions of tertiary alcohols, 39 trapping of the carbon-centered radicals generated through decarboxylation reactions, 40,41 radical functionalizations of olefins, 42−47 and azidation through C–C bond cleavage. 48 In addition to these methods, azides have been prepared by reactions at C–H bonds that are catalyzed by manganese–porphyrin complexes, that are photoinduced or promoted by visible light, or that are conducted with an oxidant such as K 2 S 2 O 8 .…”

Novel iron doped calcium oxalates as promising heterogeneous catalysts for one-pot multi-component synthesis of pyranopyrazoles

“…Relative to other expensive choices, iron is the most possible candidate for doping due to its low cost, abundance, non-toxic and environmentally benign nature. 18 The partial loading of iron in the place of Ca 2+ in CaOx can give rise to material with improved activity. Besides the chemical composition, the physical features attained by the catalysts such as morphology, size etc.…”