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We report the synthesis of quinolines using cyclopropenes and an azidobenziodazolone (ABZ) hypervalent iodine reagent as an azide radical source under visible-light irradiation. Multisubstituted quinoline products were obtained in 34-81% yield. The reaction was most efficient for 3-trifluoromethylcyclopropenes, affording valuable 4-trifluoromethylquinolines. The transformation probably proceeds through the cyclization of an iminyl radical formed by the addition of the azide radical on the cyclopropene double bond, followed by ring-opening and fragmentation.

This review presents an account of the palladium-catalyzed functionalizations of alkenes and alkynes developed at the Laboratory of Catalysis and Organic Synthesis (LCSO). Starting from the intramolecular oxy- and aminoalkynylation of alkenes, tethered methods were then developed to functionalize allylic amines and alcohols, as well as propargylic amines. Finally, a new dynamic kinetic asymmetric transformation was developed based on the use of a ‘one-arm’ Trost-type ligand, giving access to enantiopure amino alcohols. Each section is a personal account by the researcher(s) who performed the work.1 Introduction,2 Oxy- and Aminoalkynylation of Olefins,3 In Situ Tethering Strategies for the Synthesis of Vicinal Amino Alcohols and Diamines,4 Carboamination of Allylic Alcohols,5 Carbooxygenation of Propargylic Amines,6 Enantioselective Carboetherification/Hydrogenation via a Catalytically Formed Chiral Auxiliary,7 Conclusion

This review describes the development of enantioselective methods for the ring opening of cyclopropanes. Both approaches based on the reaction of nonchiral cyclopropanes and (dynamic) kinetic resolutions and asymmetric transformations of chiral substrates are presented. The review is organized according to substrate classes, starting by the more mature field of donor-acceptor cyclopropanes. Emerging methods for enantioselective ring opening of acceptor- or donor-only cyclopropanes are then presented. The last part of the review describes the ring opening of more reactive three-membered rings substituted with unsaturations with a particular focus on vinylcyclopropanes, alkylidenecyclopropanes, and vinylidenecyclopropanes. In the last two decades, the field has grown from a proof of concept stage to a broad range of methods for accessing enantioenriched building blocks, and further extensive developments can be expected in the future.

Donor–acceptor cyclopropanes substituted with 3,3-dialkyltriazenyl groups are described herein. The strong electron-donating character of the triazene renders the cyclopropanes highly reactive, allowing for catalyst-free ring-opening reactions with methanol and tetracyanoethylene under mild conditions. The triazene-substituted cyclopropanes could also be used as substrates in Lewis acid catalyzed (3 + 2) annulations with silyl enol ethers.

We report the convergent synthesis of bicyclo[3.1.0]hexanes possessing an all-carbon quaternary center via a (3 + 2) annulation of cyclopropenes with cyclopropylanilines. Using an organic or an iridium photoredox catalyst and blue LED irradiation, good yields were obtained for a broad range of cyclopropene and cyclopropylaniline derivatives. The reaction was highly diastereoselective when using difluorocyclopropenes together with a removable substituent on the cyclopropylaniline, giving access to important building blocks for medicinal chemistry. With efficient methods existing for the synthesis of both reaction partners, our method grants a fast access to highly valuable bicyclic scaffolds with three contiguous stereocenters.

The selective palladium-catalyzed carboamination of allylic alcohols is reported on the basis of the use of an easily introduced trifluoroacetaldehyde-derived tether. Aminoalkynylation reactions were realized using alkynyl bromides and commercially available phosphine ligands. For aminoarylations, a new biaryl phosphine ligand, “Fu-XPhos”, was introduced to overcome a competitive Heck pathway. The carboamination products were obtained in high yields and diastereoselectivity. The tether could be easily removed to give value-added amino alcohol building blocks.

We report herein a radical-mediated amination of cyclopropenes. The transformation proceeds through a cleavage of the three-membered ring after the addition of an azide radical on the strained double bond and leads to tetrasubstituted alkenyl nitrile derivatives upon loss of N 2 . With 1,2-diaryl substituted cyclopropenes, this methodology could be extended to a one pot synthesis of highly functionalized polycyclic aromatic compounds (PACs). This transformation allows the synthesis of nitrile-substituted alkenes and aromatic compounds from rapidly accessed cyclopropenes using only commercially available reagents.