Cyclocarbopalladation: Sequential Cyclization and C−H Activation/Stille Cross-Coupling in the Pd-5-Exo-Dig Reaction
摘要:
A new cyclization and C-H activation/Stille cross-coupling reaction on a nonactivated aromatic has been discovered. The reaction is regioselective and controlled by the stannylated reagent. Labeling experiments have been performed that provide evidence for a complete transfer of the deuterium through the coordination sphere of palladium.
6 with potassium hydroxide or sodiummethoxide in methanol at room temperature provides 1,2-dihydro[c]benzazepin-3-ones 9. The high product yields and the ease of the reactions under surprisingly mild conditions are particularly intriguing in view of the complex mechanistic pathway involved in the overall transformation. A mechanism based on a multistep rearrangement is proposed, involving conjugated
Gold(I)-Catalyzed Enantioselective Carboalkoxylation of Alkynes
作者:Weiwei Zi、F. Dean Toste
DOI:10.1021/ja407150h
日期:2013.8.28
A highly enantioselective carboalkoxylation of alkynes catalyzed by cationic (DTBM-MeO-Biphep)gold(I) complexes is reported. Various optically active β-alkoxyindanone derivatives were obtained in good yields with high enantioselectivities. Furthermore, this methodology was extended to the enantioselective synthesis of 3-methoxycyclopentenones. The reaction is proposed to proceed through an enantioselective
α-C–H Functionalization of π-Bonds Using Iron Complexes: Catalytic Hydroxyalkylation of Alkynes and Alkenes
作者:Yidong Wang、Jin Zhu、Austin C. Durham、Haley Lindberg、Yi-Ming Wang
DOI:10.1021/jacs.9b11716
日期:2019.12.18
functionalization of C-Hbonds enables streamlined and sustainable solutions to problems in synthetic organic chemistry. In this Communication, we disclose an iron-based catalytic system for the functionalization of propargylic and allylic C-Hbonds. Inexpensive and readily-available cyclopentadienyliron(II) dicarbonyl complexes were employed as catalysts for a novel deprotonative activation mode for C-H functionalization
发现基于地球丰富的过渡金属的催化体系用于 CH 键的功能化,为合成有机化学中的问题提供了简化和可持续的解决方案。在本通讯中,我们公开了一种用于炔丙基和烯丙基 CH 键功能化的铁基催化系统。廉价且容易获得的环戊二烯基 (II) 二羰基配合物被用作 CH 官能化的新型去质子活化模式的催化剂,这种方法允许不饱和结构单元与芳基醛和其他羰基亲电子试剂直接结合,以提供一系列不饱和的在操作简单和官能团耐受反应条件下的醇偶联产物。
A metal-free cascade reaction of β-halo-α,β-unsaturated aldehydes and 1,4-dithiane-2,5-diols: synthesis of polycyclic 2-formylthiophenes
A metal-free cascade reaction strategy has been developed for the synthesis of novel polycyclic 2-formylthiophenes from β-halo-α,β-unsaturatedaldehydes and 1,4-dithiane-2,5-diol. Recyclable polymer supported organic base was used to perform the reaction process. This synthetic protocol was applied to synthesize several novel polycyclic thiophenes including steroidal D-ring annelated thiophene. Our