71022-74-7Relevant articles and documents
THE FACILE SYNTHESIS OF DIIODOALKENES BY THE ADDITION OF I2 TO ALKYNES ON ALUMINA
Larson, Steven,Luidhardt, Teresa,Kabalka, George W.,Pagni, Richard M.
, p. 35 - 36 (1988)
Iodine adds to a variety of alkynes on alumina at or slightly above room temperature to form diiodoalkenes.
Iodination and iodonitration of phenylacetylene under solvent-free conditions
Tveryakova,Miroshnichenko,Perederina,Yusubov
, p. 152 - 153 (2007)
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Regio- and Stereoselective Synthesis of 1,2-Dihaloalkenes Using In-Situ-Generated ICl, IBr, BrCl, I2, and Br2
Hammond, Gerald B.,Liu, Shiwen,Xu, Bo,Yang, Yi,Yang, Yuhao,Zeng, Xiaojun
supporting information, p. 1018 - 1031 (2020/04/08)
We describe a catalyst-free 1,2-trans-dihalogenation of alkynes with an unprecedented substrate scope and exclusive regio- and stereoselectivity. This versatile dihalogenation system—a combination of NX1S electrophile and alkali metal halide (MX2) in acetic acid—is applicable for diverse categories of alkynes (electron-rich or poor alkynes, internal and terminal alkynes, or heteroatoms such as O-, N-, S-substituted alkynes). The hydrogen bonding donor solvent acetic acid is essential for the in-situ generation of X1X2 electrophile, including ICl, IBr, BrCl, I2, and Br2. Haloalkenes are not only commonly found in biologically active natural products but also have been used extensively in cross-coupling reactions. More specifically, 1,2-dihaloalkenes are especially important synthons because of the presence of two synthetic handles that open a broad avenue to expeditiously generate multisubstituted alkenes. Dihalogenation of alkynes is a straightforward way to prepare 1,2-dihaloalkenes. However, existing alkyne dihalogenation methods either rely on the use of toxic reagents, such as IBr and ICl, lack regio- and stereoselectivity or have limited substrate scope. Thus, the development of a widely applicable and yet efficient alkyne dihalogenation method is still highly desired. Here, we have addressed the aforementioned issues based on an in-situ-generated dihalogenation of reagents, such as ICl and Ibr, by using the readily available N-halosuccinimide (NXS) and alkali metal halides as halogen sources. Our method offers an unprecedented substrate scope, the regio- and stereoselectivity for the synthesis of 1,2-dihaloalkenes. Our simple and mild conditions might find wild applications in the preparation of high-value building blocks for medicines and materials. Dihaloalkenes are important raw materials for pharmaceutical and chemical industries. However, existing preparation methods suffer from a limited substrate scope as well as poor regio- and stereoselectivity. Furthermore, these methods often necessitate highly toxic reagents, such as Cl2, ICl, and BrCl. Our environmentally friendly 1,2-trans-dihalogenation is based on easy-handling halide sources, such as alkali metal halides. What is more, our method offers an unprecedented substrate scope, the regio- and stereoselectivity for the synthesis of 1,2-dihaloalkenes.
Chemoselective and stereospecific iodination of alkynes using sulfonium iodate(i) salt
Rao, Dodla S.,Reddy, Thurpu R.,Kashyap, Sudhir
, p. 1508 - 1518 (2018/03/08)
An efficient and highly chemoselective iodination of alkynes using a sulfonium iodate(i) electrophilc reagent under metal-free conditions has been realized. The reactivity of sulfonium iodate(i) salt could be significantly diverse in the presence of water
Cobalt-catalyzed stereoselective iodosulfonylation and diiodination of alkynes via oxidation of potassium iodide in air
Taniguchi, Nobukazu
, p. 1454 - 1460 (2018/02/15)
Cobalt-catalyzed iodosulfonylation of alkynes can be achieved using sodium sulfinates in the presence of KI. This procedure produces numerous stereoselective (E)-β-iodoalkenyl sulfones with good yields and suppresses the formation of diiodoalkenes. Furthermore, when this reaction is performed in the absence of sodium sulfinates, the expected (E)-diiodoalkenes are obtained.
