Rh(II)-Catalyzed [2,3]-Sigmatropic Rearrangement of Sulfur Ylides Derived from Cyclopropenes and Sulfides
作者:Hang Zhang、Bo Wang、Heng Yi、Yan Zhang、Jianbo Wang
DOI:10.1021/acs.orglett.5b01542
日期:2015.7.2
Rh2(OAc)4-catalyzed [2,3]-sigmatropicrearrangement of sulfurylides is reported. A series of cyclopropenes were successfully employed for [2,3]-sigmatropicrearrangement by a reaction with either allylic or propargylic sulfides. Under the optimized conditions, the reaction afforded the products in moderate to excellent yields. In these transformations, the vinyl metal carbenes generated in situ from the cyclopropenes
Mild Ring‐Opening 1,3‐Hydroborations of Non‐Activated Cyclopropanes
作者:Di Wang、Xiao‐Song Xue、Kendall N. Houk、Zhuangzhi Shi
DOI:10.1002/anie.201811036
日期:2018.12.17
The Brown hydroboration reaction, first reported in 1957, is the addition of B−H across an olefin in an anti‐Markovnikov fashion. Here, we solved a long‐standing problem on mild 1,3‐hydroborations of non‐activated cyclopropanes. A three‐component system including cyclopropanes, boron halides, and hydrosilanes has been developed for borylative ring‐opening of cyclopropanes following the anti‐Markovnikov
B(C<sub>6</sub>
F<sub>5</sub>
)<sub>3</sub>
-Catalyzed Ring Opening and Isomerization of Unactivated Cyclopropanes
作者:Zi-Yu Zhang、Zhi-Yun Liu、Rui-Ting Guo、Yu-Quan Zhao、Xiang Li、Xiao-Chen Wang
DOI:10.1002/anie.201700864
日期:2017.3.27
Catalytic amounts of B(C6F5)3 promote the ring opening and subsequent isomerization of a series of unactivated cyclopropanes to afford terminal olefins in good yields when a hydrosilane and 2,6‐dibromopyridine are employed as additives.
催化量的B(C 6 F 5)3促进开环和随后一系列未活化环丙烷的异构化,从而在使用氢化硅烷和2,6-二溴代吡啶作为添加剂时以高收率提供末端烯烃。
Controllable, Sequential, and Stereoselective C–H Allylic Alkylation of Alkenes
作者:Ling Qin、Mohammed Sharique、Uttam K. Tambar
DOI:10.1021/jacs.9b08801
日期:2019.10.30
new C-C bonds represents a powerful approach to generate complex molecules from simple starting materials. However, a general and controllable method for the sequential conversion of a methyl group into a fully substituted carbon center remains a challenge. We report a new method for the selective and sequential replacement of three C-H bonds at the allylicposition of propylene and other simple terminal
将 CH 键直接转化为新的 CC 键代表了一种从简单的起始材料生成复杂分子的强大方法。然而,将甲基顺序转化为完全取代的碳中心的通用且可控的方法仍然是一个挑战。我们报告了一种新方法,用于选择性和顺序替换丙烯和其他简单末端烯烃的烯丙基位置的三个 CH 键,该烯烃具有源自格氏试剂的不同碳基团。铜催化剂和富电子联芳膦配体有助于以高支链选择性形成烯丙基烷基化产物。我们还提出了在催化铜和手性膦配体存在下生成对映体富集的烯丙基烷基化产物的条件。通过这种方法,
The reaction of α-methoxyvinyllithium with trialkylboranes
作者:Alan B. Levy、Steven J. Schwartz、Nancy Wilson、Bradley Christie
DOI:10.1016/s0022-328x(00)84870-6
日期:1978.8
Several alkenyltrialkylborate salts derived from the reaction of α-methoxyvinyllithium (MVL) with trialkylboranes have been prepared. At −80°C, the initial complex is stable as indicated by its iodination to give moderate yields of enol ethers. Warming the complex to room temperature leads via an alkyl group migration to a new alkenyldialkylmethoxyborate salt. Oxidation of this complex leads to methyl