Fluorinative ring-opening of cyclopropanes by hypervalent iodine reagents. An efficient method for 1,3-oxyfluorination and 1,3-difluorination

Abstract

Reaction of 1,1-disubstituted cyclopropanes with hypervalent iodines in the presence of AgBF4 leads to 1,3-difluorination and 1,3-oxyfluorination products.

Ring‐Opening Regio‐, Diastereo‐, and Enantioselective 1,3‐Chlorochalcogenation of Cyclopropyl Carbaldehydes

“…Recently,t he Szabó group generated 1,3-difluorides from 1,1-disubstituted cyclopropanes, [2,3] whereas our group synthesized1 ,3-dichloridesf rom donor-acceptor cyclopropanes. [4,5] Sparr andG ilmour reported the use of aldehyde-functionalized cyclopropanes for an asymmetric 1,3-dichlorination, [6] making use of am erged iminium-enamine activation (Scheme 1).…”

Electrochemical Vicinal Difluorination of Alkenes: Scalable and Amenable to Electron‐Rich Substrates

“…While acid sensitive functionality, such as boc groups, was not tolerated, [26] a cyclopropyl ring (2 t) avoided competing oxidative ring opening. [30] The scalability of the method was demonstrated by yielding gram-scale quantities of products 3 e, 3 i and 3 s and a deca-gram-scale quantity of 3 s. In each of these cases, 70 + % of pure iodotoluene was recovered. The commercially available ElectraSyn 2.0 set-up was also tested-in combination with a PTFE vial-and was found to give product 3 d in a comparable yield to our set-up, validating the robustness of the conditions.…”

Hypervalent‐Iodine‐Mediated Carbon–Carbon Bond Cleavage and Dearomatization of 9H‐Fluoren‐9‐ols

“…[8] Herein we report ad omino reaction mediated by hypervalent iodine for the synthesis of spiro-ethers from 9Hfluoren-9-ols (Scheme 1c). [9][10][11] It features an unprecedented arylÀC(sp 3 )b ond cleavage promoted by hypervalent iodine, and the mechanism might be different from the metalpromoted b-elimination or radical b-scission discussed above. Ther ing-opening products quickly underwent oxidative dearomatization/cyclization to produce an oxo-spiro scaffold.…”