Multicomponent Synthesis of Pyrroles from Cyclopropanes: A One-Pot Palladium(0)-Catalyzed Dehydrocarbonylation/Dehydration
作者:William J. Humenny、Polydoros Kyriacou、Katarina Sapeta、Avedis Karadeolian、Michael A. Kerr
DOI:10.1002/anie.201206177
日期:2012.10.29
es yields tetrahydro‐1,2‐oxazines, which in turn undergo a Tsuji dehydrocarbonylation to give dihydro‐1,2‐oxazines (see scheme; dba=dibenzylideneacetone). Addition of base to this reaction mixture results in clean conversion to pyrroles. The result is a flexible three‐component strategy for the synthesis of tetrasubstituted pyrroles.
Synthesis of Exclusively 4-Substituted β-Lactams through the Kinugasa Reaction Utilizing Calcium Carbide
作者:Abolfazl Hosseini、Peter R. Schreiner
DOI:10.1021/acs.orglett.9b01192
日期:2019.5.17
A new Kinugasa reaction protocol has been elaborated for the one-pot synthesis of 4-substituted β-lactams utilizing calcium carbide and nitrone derivatives. Calcium carbide is thereby activated by TBAF·3H2O in the presence of CuCl/NMI. The ease of synthesis and use of inexpensive chemicals provides rapid access of practical quantities of β-lactams exclusively substituted at position 4.
Syntheses of 2-Iminoindolin-3-ones and 2-Alknyl-2,3-dihydroquinazolin-4(1<i>H</i>)-ones from 3-Diazoindolin-2-imines
作者:Zhenwei Lin、Jing Qian、Ping Lu、Yanguang Wang
DOI:10.1021/acs.joc.0c01548
日期:2020.9.18
into 2-alknyl-2,3-dihydroquinazolin-4(1H)-ones through a Ag(I)-catalyzed reaction with terminal alkynes. A MeOH-triggered ring expansion mechanism involving cyclic iminium formation and nucleophilic addition is proposed for this novel alkynylation reaction. This two-step procedure provides a general and convenient approach to 2-alknyl-2,3-dihydroquinazolin-4(1H)-ones, which are privileged structures
The asymmetricKinugasareaction was performed on pure water for the first time without the need for any organic co‐solvents. In contrast to most asymmetricKinugasareactions, trans‐β‐lactams were obtained as the major products in good yields, enantioselectivities, and diastereoselectivities (up to 90 % yield, 98 % ee, and >99:1 d.r.). This reaction is atom‐economical, environmentally friendly, and
Copper-Catalyzed Asymmetric Kinugasa/Michael Addition Cascade Reactions for the Synthesis of Chiral Spiro β-Lactams
作者:Yunlin Ao、Haowen Ma、Binghan Gan、Wenjing Wang、Jiehao Zhang、Wei Zhou、Xiaoqi Zhang、Qian Cai
DOI:10.1021/acs.orglett.4c01568
日期:2024.6.7
A mild copper-catalyzed asymmetric Kinugasa/Michael addition cascade process is developed. The reaction of α, β-unsaturated ester-tethered propiolamides with nitrones provides an efficient protocol for the construction of functionalized chiral 2,6-diazaspiro[3.4]octane-1,5-dione products in satisfactory yields and with high enantio- and diastereoselectivities.