Enantioselective Carbonyl Propargylation by Iridium-Catalyzed Transfer Hydrogenative Coupling of Alcohols and Propargyl Chlorides
作者:Sang Kook Woo、Laina M. Geary、Michael J. Krische
DOI:10.1002/anie.201203334
日期:2012.7.27
It takes alkynes! Exposure of propargylchlorides to primary benzylic alcohols in the presence of [Ir(cod)(R)‐segphos}]OTf (cod=1,5‐cyclooctadiene, segphos=5,5′‐bis(diphenylphosphino)‐4,4′‐bi‐1,3‐benzodioxole, Tf=trifluoromethanesulfonyl) results in hydrogen exchange to give allenyliridium–aldehyde pairs that combine to form products of propargylation with high ee value (see scheme). The reaction
The first iron-catalysed cross coupling of propargyl electrophiles with lithium alkenylborates has been developed. Various propargyl electrophiles can be cross-coupled with lithium (E)- or (Z)-alkenylborates in a stereospecific manner to afford the corresponding 1,4-enynes in good to excellent yields. The reaction features high SN2-type regioselectivity and functional group compatibility.
Cu(I)-Catalyzed 1,2-Alkynyl-propargylation and -benzylation of Benzyne Derivatives
作者:Qile Wang、Thomas R. Hoye
DOI:10.1021/acs.orglett.1c01788
日期:2021.7.16
We report here a three-component, Cu(I)-catalyzed hexadehydro-Diels–Alder (HDDA) benzyne 1,2-difunctionalization reaction. This protocol allowed the introduction of two different carbon-based substituents onto the in situ-generated benzyne. These substituents were terminal monoynes or diynes partnered with propargylic, benzylic, or allylic chlorides. An example of a sequential HDDA reaction is demonstrated
作者:Zhenyu Zhang、Wei Zhang、Jun−Chen Tang、Jin−Teng Che、Zhongchao Zhang、Jia−Hua Chen、Zhen Yang
DOI:10.1021/acs.joc.3c00542
日期:2023.8.4
(+)-Haperforin G was synthesized in 20 steps from commercially available starting materials. A Co-catalyzed intramolecular Pauson–Khand reaction was used for stereoselective construction of cyclopentanone bearing an all-carbon quaternary stereogenic center at the bridge-head position. Light-initiated photocatalysis was used for convergent and asymmetric cross-coupling of the unstabilized C(sp3) radical
(+)-Haperforin G 由市售起始原料经过 20 个步骤合成。共催化分子内 Pauson-Khand 反应用于立体选择性构建在桥头位置带有全碳四元立构中心的环戊酮。光引发的光催化用于不稳定的C(sp 3 )自由基与烯酮的会聚和不对称交叉偶联。所开发的化学方法为合成结构多样的 haperforin G 类似物铺平了道路 ( 6 )。