描述了基于环己-1,4-二烯的气态碘化氢替代品的设计和克级合成。通过用中等强度的布朗斯台德酸引发,碘化氢从替代物转移到 CC 多重键上,例如炔烃和丙二烯,而没有游离碘化氢的参与。代用品碎片化为甲苯和乙烯,易挥发废物。这种氢碘化反应避免了对碘化氢或氢碘酸的不稳定处理。通过这种方式,可以以立体控制的方式访问范围广泛的以前未知或难以制备的乙烯基碘。
Rhodium‐Catalyzed Anti‐Markovnikov Transfer Hydroiodination of Terminal Alkynes**
作者:Philip Boehm、Niklas Kehl、Bill Morandi
DOI:10.1002/anie.202214071
日期:2023.1.23
We report a shuttle approach for the Rh-catalyzed anti-Markovnikov hydroiodination of terminalalkynes to vinyl iodides. For aliphatic alkynes, a ligand- and substrate-dependent stereodivergence is observable. The vinyl iodides are engaged in a variety of C−C and C−X bond-forming reactions. The method is used to shorten a synthetic sequence to a cis-fatty acid. Deuterium-labeling and stoichiometric
Markovnikov-type hydroiodination of terminal alkynes with iodine and Ph2P(O)H took place selectively to afford the corresponding internal iodoalkenes in good yields. Combination of (PhO)(2)P(O)H and Ph2P(O)OH instead of Ph2P(O)H also provided internal iodoalkenes in excellent yields. This hydroiodination is advantageous in terms of mild conditions, convenient operation, and tolerance to various functional groups. In addition, direct synthesis of internal iodoalkenes from silylalkynes was also achieved by using a mixed system of iodine and phosphorus reagents. (c) 2012 Elsevier Ltd. All rights reserved.