不对称氢化是制备单一对映体化合物的最有效方法之一。然而,在具有多个不饱和键的底物中相对惰性的不饱和基团的化学和对映选择性氢化仍然是一个挑战。我们在此报告了共轭烯炔的高度化学和对映选择性氢化同时保持炔键完整的协议。机理研究表明,Co II 配合物的锌还原产生的伴随的 Zn 2+在启动合理的 Co I /Co III催化循环中起着关键作用。这种方法可以高效生成手性炔丙胺(高达 99.9 % ee 和 2000 S/C)和进一步有用的化学转化。
DBU-Promoted [4 + 4] Domino Cycloaddition of Ynones with Benzylidenepyrazolones To Access Eight-Membered Cyclic Ethers
作者:Cheng Cheng、Jiayong Zhang、Xue Wang、Zhiwei Miao
DOI:10.1021/acs.joc.8b00352
日期:2018.5.18
of ynones and benzylidenepyrazolones has been developed. This process resulted finally in the formation of eight-memberedcyclicethers in moderate to good yields. The easy availability of starting materials and the simple cyclization procedure make this approach suitable for the preparation of a wide range of useful oxocino [2,3-c] pyrazoles.
已经开发出有效的DBU促进的炔酮和亚苄基吡唑并酮的[4 + 4]多米诺环化反应。该过程最终导致中等至良好产率的八元环醚的形成。起始原料的容易获得和简单的环化程序使该方法适合于制备各种有用的氧代[2,3- c ]吡唑。
1,5-hydrogen atomtransfer (1,5-HAT) strategy for the remote C(sp3)–H functionalization reaction, which includes cyanation, oxidation, and etherification under visible-light-induced photochemical conditions. This reaction is achieved using readily available alkyl N-hydroxyphthalimide esters as radical precursors, which can efficiently react with diverse alkynes to form key vinyl radical intermediates
A tertiary phosphine-mediated [3+2] cyclization reaction of ynones with fluorinated coumarin derivatives has been developed to give a series of coumarin-based CF3-containing furanones in moderate to good yields under mild reaction conditions. Preliminary investigation into their antitumor activities is also presented.