报道了使用 Rh(II) 作为催化剂的 1,6- 和 1,7- 烯炔的骨架重组导致 1-乙烯基环烯烃。可以获得两种可能的 1-乙烯基环烯烃异构体,I 型和 II 型,它们的比例高度依赖于所用烯炔的取代模式。I 型化合物的形成涉及 CC 双键的单次断裂,其产物与烯炔复分解的产物相同。相比之下,II 型化合物的形成涉及 CC 双键和三键的双裂解,其具有异常的键连接。炔烃碳上的苯基和内部烯烃碳上的甲基的存在促进了 II 型化合物的形成。芳环上取代基的电子和空间性质也影响 I 型和 II 型的比例。系绳的性质也对反应过程有显着影响。还报告了环丙基铑卡宾(烯炔骨架重组的关键中间体)作为中间体的实验证据。除了烯炔的骨架重组外,Rh(II) 配合物还被发现对炔衍生物的一些环化异构化反应具有很高的催化活性,包括烯炔双环化为双环[4.1.0]庚烯衍生物和炔基呋喃环化为苯酚衍生物。还报道了烯炔骨架重组的关键中
Radical Borylation/Cyclization Cascade of 1,6-Enynes for the Synthesis of Boron-Handled Hetero- and Carbocycles
作者:Shi-Chao Ren、Feng-Lian Zhang、Jing Qi、Yun-Shuai Huang、Ai-Qing Xu、Hong-Yi Yan、Yi-Feng Wang
DOI:10.1021/jacs.7b01889
日期:2017.5.3
construct boron-handled cyclic molecules was developed based on a radical borylation/cyclization cascade of 1,6-enynes. The process was initiated by the chemo- and regio-controlled addition of an N-heterocyclic carbene-boryl radical to an alkene or alkyne, followed by ring closure to afford boron-substituted cyclic skeletons. Further molecular transformations of the cyclic products to synthetically
Enantioselective Synthesis of 3-Azabicyclo[4.1.0]heptenes and 3-Azabicyclo[3.2.0]heptenes by Ir-Catalyzed Asymmetric Allylic Amination of<i>N</i>-Tosyl Propynylamine and Pt-Catalyzed Cycloisomerization
作者:Ji-Bao Xia、Wen-Bo Liu、Tian-Min Wang、Shu-Li You
DOI:10.1002/chem.201000467
日期:2010.6.11
Irresistible! Highly regio‐ and enantioselective Ir‐catalyzed allylicamination reactions of N‐tosyl propynylamines have been realized. The resulting N‐tosyl allylpropynylamines were transformed into highly enantioenriched 3‐azabicyclo[4.1.0]heptenes and 3‐azabicyclo[3.2.0]heptenes, respectively, in the presence of PtCl2 (see scheme; Ts=tosyl, cod=1,5‐cyclooctadiene, TBAF=tetrabutylammonium fluoride
The cyclopentadienyl (Cp) group is a very important ligand for many transition‐metal complexes which have been applied in catalysis. The availability of chiralcyclopentadienyl ligands (Cpx) lags behind other ligand classes, thus hampering the investigation of enantioselective processes. We report a library of chiral CpxIrIII complexes equipped with an atropchiral Cp scaffold. A robust complexation
环戊二烯基(Cp)基团是许多在催化中应用的过渡金属配合物的重要配体。手性环戊二烯基配体(Cp x)的可用性落后于其他配体类别,因此妨碍了对映选择性过程的研究。我们报告了配备手性Cp支架的手性Cp x Ir III复合物的库。强大的络合程序可为Cp x Ir III络合物可靠地提供可调节的抗衡离子。在概念验证的应用中,含碘化物对烯炔的环异构化反应具有很高的选择性。脱氢哌啶稠合的环丙烷产物以良好的产率和对映选择性形成。
Rhodium(I)-Catalyzed Cycloisomerization of 1,6-Enynes to Bicyclo[4.1.0]heptenes
作者:Sun Young Kim、Young Keun Chung
DOI:10.1021/jo902273x
日期:2010.2.19
Efficient rhodium(I)-catalyzed cyclopropanation reactions of nitrogen-tethered 1,6-enynes to azabicyclo[4.1.0]heptenes are reported. Moreover, rhodium(I)-catalyzed tandem cycloisomerization and carbonylative [3+3+1] cycloaddition reactions of a cyclopropylenyne have been observed.
The long and winding Rhoad: The asymmetriccycloisomerization of nitrogen‐ and oxygen‐bridged 1,6‐enynes proceeded in the presence of a cationic rhodium complex that was coordinated by PPh3 and a chiral diene ligand to afford high yields of chiral 3‐aza‐ and 3‐oxabicyclo[4.1.0]heptenes and high enantioselectivities. TS=4‐toluenesulfonyl, Tf=trifluoromethanesulfonyl.