indoles and alkynes for the assembly of tetrasubstituted alkenes is reported. The carbamoyl directing group migrates to the carbon of the alkene moiety of the products through rare Rh-catalyzed C–N bond cleavage after the C–H alkenylation step and thus acts as an internal amidation reagent. This protocol shows broad substrate scope, excellent regio/stereoselectivity, and good to excellent yields.
Chemoselective N-Acylation of Indoles and Oxazolidinones with Carbonylazoles
作者:Stephen T. Heller、Erica E. Schultz、Richmond Sarpong
DOI:10.1002/anie.201203976
日期:2012.8.13
Unique reactivity: In the presence of more reactive amine and alcohol functional groups and of carboxylic acids, the chemoselective N‐acylation of indoles (see scheme) and oxazolidinones is achieved by taking advantage of the unique reactivity of carbonylazole acylating agents with catalytic amounts of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU).
economical and stereoselective synthesis of tetrasubstituted α,β‐unsaturated amides was achieved by a Cp*CoIII‐catalyzed C−H alkenylation/directing group migration sequence. A carbamoyl directing group, which is typically removed after C−H functionalization, worked as an internal acylating agent and migrated onto the alkene moiety of the product. The directing group migration was realized with the
通过Cp * Co III催化的CH烯基化/方向基团迁移序列,实现了高度原子经济和立体选择性的四取代α,β-不饱和酰胺的合成。通常在CH官能化后被除去的氨基甲酰基导向基团作为内部酰化剂起作用,并迁移到产物的烯烃部分上。使用Cp * Co III催化剂可实现导向基团的迁移,而相关的Cp * Rh III催化剂则不会促进迁移过程。将产物进一步转化为两种类型的三环化合物,其中一种具有荧光性质。
Rhodium(III)-Catalyzed Enantioselective Coupling of Indoles and 7-Azabenzonorbornadienes by C−H Activation/Desymmetrization
作者:Xifa Yang、Guangfan Zheng、Xingwei Li
DOI:10.1002/anie.201811998
日期:2019.1.2
Chiral rhodium(III) cyclopentadienyl catalysts (CpXRhIII) play significant roles in asymmetric arene C−Hactivation. Rh/Ir‐catalyzed couplings of arenes and strained rings have been well‐studied, but they have been limited to racemic systems. Reported in this work is the CpxRhIII/AgSbF6‐catalyzed enantioselective desymmetrizative C−C coupling of N‐pyrimidylindoles and 7‐azabenzonorbornadienes with
手性铑(III)环戊二烯基催化剂(Cp X Rh III)在不对称芳烃CH活化中起重要作用。芳烃和应变环的Rh / Ir催化偶联已得到了很好的研究,但仅限于外消旋体系。这项工作报告的是Cp x Rh III / AgSbF 6催化的N-嘧啶吲哚和7-氮杂苯并降冰片二烯的对映选择性脱对称CC偶联,具有较高的效率和对映选择性。AgSbF 6的作用已经通过机理研究确定。AgSbF 6 通过抑制吲哚的C3-H活化来增强催化活性,否则该活化将导致催化不活泼的物种。
Metal-Free Directed Diastereoselective C2,C3-Cyclopropanation of Substituted Indoles with Diazoesters
作者:Jayanta Ghorai、Pazhamalai Anbarasan
DOI:10.1021/acs.orglett.9b01197
日期:2019.5.3
A metal-free directed C2,C3-cyclopropanation of suitably substitutedindoles with α-diazo esters has been accomplished for the diastereoselective synthesis of cyclopropane-fused indolines in good yield. This method works well with a wide range of differently substituted α-diazo esters as well as indole derivatives and shown excellent compatibility for diverse directing group like pyridyl, pyrimidyl