Mild Cu(I)-Catalyzed Cascade Reaction of Cyclic Diaryliodoniums, Sodium Azide, and Alkynes: Efficient Synthesis of Triazolophenanthridines

Abstract

Linear iodoniums are widely used as arylating reagents. However, cyclic diaryl idodoniums are ignored despite their potential to initiate dual arylations, atom and step economically. In our current work, a three-component cascade reaction of cyclic diaryliodoniums, sodium azide, and alkynes has been successfully achieved under mild conditions, catalyzed by cheap copper species. The regioselectivity associated with unsymmetrical iodoniums was enhanced by installing two methyls ortho and para to the I(III) center. The reaction enables a rapid access to a variety of complex molecules, triazolophenanthridine derivatives.

Preparation and X-ray Structural Study of Dibenziodolium Derivatives

“…The preparation of triflate 10 by a similar procedure was previously reported by Wen and coauthors. 44,45 The structure of dibenziodolium bis(triflyl)imidate 11 was established by single-crystal X-ray crystallography (Figures 1 and 2). Two different pseudopolymorphs of the product 11 were studied by X-ray crystallography.…”

“…Recently, the in situ generation of azide 14d and its use in the efficient synthesis of triazolophenanthridines have been reported. 45 …”

Conversion of 2‐Iodobiaryls into 2,2′‐Diiodobiaryls via Oxidation‐Iodination Sequences: A Versatile Route to Ladder‐Type Heterofluorenes

“…[24] In summary,w eh ave developed ac onvenient two-step method for the preparation of 2,2'-diiodobiaryls from readily accessible 2-iodobiaryls through oxidative cyclization/Cucatalyzed iodinative ring-opening sequences.E ven though cyclic diaryliodonium intermediates have previously been reported to serve as direct precursors to carbazoles and some other bridged biaryl compounds, [19,30] the method presented herein should substantially enhance their utility for the synthesis of aw ide range of heterofluorenes.I ndeed, the versatility of this method has been demonstrated by the preparation of novel tetraiodoteraryls and their conversion into various ladder-type p-conjugated systems.F urthermore, the present method may also be useful for the diversification of Kitas 2,2'-diiodobiaryl-based organocatalysts for oxidation reactions. [24] In summary,w eh ave developed ac onvenient two-step method for the preparation of 2,2'-diiodobiaryls from readily accessible 2-iodobiaryls through oxidative cyclization/Cucatalyzed iodinative ring-opening sequences.E ven though cyclic diaryliodonium intermediates have previously been reported to serve as direct precursors to carbazoles and some other bridged biaryl compounds, [19,30] the method presented herein should substantially enhance their utility for the synthesis of aw ide range of heterofluorenes.I ndeed, the versatility of this method has been demonstrated by the preparation of novel tetraiodoteraryls and their conversion into various ladder-type p-conjugated systems.F urthermore, the present method may also be useful for the diversification of Kitas 2,2'-diiodobiaryl-based organocatalysts for oxidation reactions.…”

Atom‐Economical Applications of Diaryliodonium Salts

“…The Wen group described another Cu‐catalyzed three‐component cascade reaction of cyclic diaryliodonium salts, sodium azide, and alkynes for the construction of triazolophenanthridines (Scheme ) . A broad range of aryl alkynes and symmetrical cyclic diaryliodonium salts provided the desired products in good to excellent yields except with strong electron‐donating groups (‐OMe) and strong electron‐withdrawing groups (‐NO 2 ) in the aryl alkynes.…”