Copper(II)-Catalyzed Exo and Enantioselective Cycloadditions of Azomethine Imines
摘要:
A strategy for exo and enantioselective 1,3-dipolar cycloaddition of azomethine imines to 2-acryloyl-3-pyrazolidinone is described. The corresponding cycloadducts are isolated with high diastereoselectivities (up to >96:4 exo/endo) and enantioselectivities (up to 98% ee).
Synthesis of Indenopyrazole Frameworks via Cascade C–H Functionalization/[3 + 2] Dipolar Cycloaddition/Aromatization Rearrangement Reactions
作者:Min Wu、Ruiqi Wang、Fangyuan Chen、Weijie Chen、Zhi Zhou、Wei Yi
DOI:10.1021/acs.orglett.0c02506
日期:2020.9.18
redox-neutral Ir(III)- or Ru(II)-catalyzed C–H couplings of azomethine imines with α,α-difluoromethylene alkynes have been realized, leading to the efficient synthesis of indenopyrazole frameworks via a tandem C–H functionalization/[3 + 2] dipolar cycloaddition/ring-opening aromatization rearrangement process, in which the generated fluoroallene species was involved as the dipolarophile via a selective
Enantioselective synthesis of indenopyrazolopyrazolones enabled by dual directing groups-assisted and rhodium(III)-catalyzed tandem C-H alkenylation/[3 + 2] stepwise cycloaddition
作者:Min Wu、Hui Gao、Huiying Xu、Wei Yi、Zhi Zhou
DOI:10.1016/j.cclet.2021.08.004
日期:2022.2
CpXRh(III)-catalyzed asymmetric cascade C-H coupling/intramolecular cyclization of azomethine imines with propargyl carbonates has been developed, affording a variety of chiral tetracyclic indenopyrazolopyrazolone frameworks with good substrate/functional group tolerance and enantioselectivity (up to 97:3 er). Combined experimental studies and DFT calculations revealed the Rh(III)-catalyzed stepwise
已经开发了Cp X Rh(III) 催化的不对称级联 CH 偶联/偶氮甲亚胺与碳酸炔丙酯的分子内环化,提供了多种手性四环茚并吡唑并吡唑啉酮骨架,具有良好的底物/官能团耐受性和对映选择性(高达 97:3 er )。结合实验研究和 DFT 计算揭示了 Rh(III) 催化的逐步环化过程,并阐明了双导向基团在调节选择性方面的协同配位模式。
Allylic Acetals as Acrolein Oxonium Precursors in Tandem C−H Allylation and [3+2] Dipolar Cycloaddition
作者:Heeyoung Lee、Dahye Kang、Sang Hoon Han、Rina Chun、Ashok Kumar Pandey、Neeraj Kumar Mishra、Sungwoo Hong、In Su Kim
DOI:10.1002/anie.201903983
日期:2019.7.8
The ruthenium(II)‐catalyzedC−Hfunctionalization of (hetero)aryl azomethine imines with allylic acetals is described. The initial formation of allylidene(methyl)oxoniums from allylic acetals could trigger C(sp2)−H allylation, and subsequent endo‐type [3+2] dipolar cycloaddition of polar azomethine fragments to deliver valuable indenopyrazolopyrazolones. The utility of this method is showcased by the
Concise Synthesis of Spirocyclic Dihydrophthalazines through Spiroannulation Reactions of Aryl Azomethine Imines with Cyclic Diazo Compounds
作者:Xinyuan Cai、Xia Song、Qiuhui Zhu、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.joc.2c01312
日期:2022.8.19
imine-assisted cylcometalation, Rh-carbene formation through dediazonization, and migratory insertion followed by reductive elimination and azomethine imine ring opening. Control experiments revealed that air acts as an effective and sustainable co-oxidant to facilitate the cascade reaction. In general, this concisesynthesis of the unprecedented spirocyclic dihydrophthalazine derivatives has advantages such as
The (R)-3,3′-(3,5-(CF3)2-C6H3)2-BINOL–boron–complex-catalyzed asymmetric 1,3-dipolar cycloaddition of β-trifluoromethyl α,β-unsaturated ketone with N,N′-cyclic azomethine imines was developed to afford N,N′-bicyclic pyrazolidine derivatives bearing a stereogenic carbon center containing CF3 motifs in high yields with excellent diastereo- and enantioselectivities (up to >20:1 dr, and >99% ee). This
( R )-3,3′-(3,5-(CF 3 ) 2 -C 6 H 3 ) 2 -BINOL-硼络合物催化β-三氟甲基α,β-的不对称1,3-偶极环加成开发了具有N,N'-环偶氮甲碱亚胺的不饱和酮,以高产率提供具有含 CF 3基序的立体碳中心的N,N'-双环吡唑烷衍生物,具有优异的非对映和对映选择性(高达 >20:1 dr,和 >99% ee)。该催化体系具有反应条件温和、效率高、底物范围广等特点。