我们已经开发了一种通过一锅合成的苯并[ b ]芴酮的方法,该方法是通过钴催化的氧杂双环烯烃的[3 + 2]环化反应,然后以开环/脱水顺序进行的,收率很好。我们小组首先探索使用2-(1-甲基肼基)吡啶(MHP)作为苯甲酰肼的CH官能化中的双齿导向基团,新的反应顺序进行得很顺利,并能耐受各种官能团,具有便利的可扩展性。值得注意的是,氧气在反应系统中充当绿色氧化剂。仔细调整反应参数可确保通过二氢环氧苯并芴酮中间体的芳构化直接合成苯并[ b ]芴酮。
Iridium-Catalyzed Asymmetric Ring-Opening of Oxabenzonorbornadienes with N-Substituted Piperazine Nucleophiles
作者:Wen Yang、Renshi Luo、Dingqiao Yang
DOI:10.3390/molecules201219748
日期:——
Iridium-catalyzed asymmetric ring-opening of oxabenzonorbornadienes with N-substituted piperazines was described. The reaction afforded the corresponding ring-opening products in high yields and moderate enantioselectivities in the presence of 2.5 mol % [Ir(COD)Cl]2 and 5.0 mol % (S)-p-Tol-BINAP. The effects of various chiral bidentate ligands, catalyst loading, solvent, and temperature on the yield and enantioselectivity were also investigated. A plausible mechanism was proposed to account for the formation of the corresponding trans-ring opened products based on the X-ray structure of product 2i.
Three-Component Cycloaddition To Synthesize Aziridines and 1,2,3-Triazolines
作者:Shuqi Chen、Yongqi Yao、Wen Yang、Qifu Lin、Lin Wang、Huanyong Li、Donghan Chen、Yun Tan、Dingqiao Yang
DOI:10.1021/acs.joc.9b01713
日期:2019.9.20
An efficient three-component cycloaddition of oxa(aza)bicyclic alkenes/norbornene in the presence of NaN3 and arylsulfonyl chlorides was developed, affording the corresponding aziridine products in good yields (up to 82%) with moderate to good endo/exo selectivities (up to >99:1 endo/exo). Further studies showed that the cycloaddition of oxa(aza)bicyclic alkenes in the presence of NaN3 and chloroalkanes
High‐valent cyclopentadienyl cobalt catalysis is a versatile tool for sustainable C−H bond functionalizations. To harness the full potential of this strategy, control of the stereoselectivity of these processes is necessary. Herein, we report highly enantioselective intermolecular carboaminations of alkenes through C−H activation of N‐phenoxyamides catalyzed by CoIII‐complexes equipped with chiral
高价的环戊二烯基钴催化是实现可持续CH键功能化的通用工具。为了充分利用这种策略的潜力,必须控制这些过程的立体选择性。在本文中,我们报道了通过配备有手性环戊二烯基(Cp x)配体的Co III络合物催化的N苯氧酰胺的C H活化,对烯烃进行高度对映选择性的分子间碳胺化反应。该方法可在非常温和的条件下将广泛使用的丙烯酸酯以及双环烯烃转化为有吸引力的对映体富集的异酪氨酸衍生物,以及经过精制的氨基取代的双环支架。概述的反应性是Cp x Co III特有的 与4d和5d贵金属催化剂的反应性互补。
Directing-Group-Controlled Ring-Opening Addition and Hydroarylation of Oxa/azabenzonorbornadienes with Arenes via C–H Activation
作者:Keyang Zhang、Ruhima Khan、Jingchao Chen、Xuexin Zhang、Yang Gao、Yongyun Zhou、Kangkui Li、Youxian Tian、Baomin Fan
DOI:10.1021/acs.orglett.0c00765
日期:2020.5.1
rhodium-catalyzed additionreaction of oxa/azabicylic alkenes with aromatic ketones and benzoic acids has been developed. The ketones and benzoic acids afforded different addition products when reacted with oxa/azabicyclic alkenes. The reaction between ketones and azabenzonorbornadienes furnished the ring-opening addition products. The reaction between benzoic acids and aza/oxabicyclic alkenes proceeded in
Palladium-Catalyzed <i>syn</i>-Stereocontrolled Ring Opening of Oxabicyclic Alkenes with Arylsulfonyl Hydrazides
作者:Donghan Chen、Yongqi Yao、Wen Yang、Qifu Lin、Huanyong Li、Lin Wang、Shuqi Chen、Yun Tan、Dingqiao Yang
DOI:10.1021/acs.joc.9b01957
日期:2019.10.4
A novel palladium-catalyzed ring-opening reaction of oxabicyclic alkenes with arylsulfonylhydrazides was first developed. In this work, we provide an efficient one-pot reaction to afford the corresponding cis-2-aryl-1,2-dihydronaphthalen-1-ols and 2-aryl-naphthalenes in moderate to excellent yields (up to 95%) under an open-air condition. Various types of functional groups attached to the substrates