Regiospecific carbon—carbon bond formation at α and β positions in cyclic ketones via double Michael addition to α-methylene-β-alkoxy cyclic ketone

1981 ◽  
Vol 22 (2) ◽  
pp. 119-122 ◽  
Author(s):  
Takashi Takahashi ◽  
Kimihiko Hori ◽  
Jiro Tsuji
Keyword(s):  
Michael Addition ◽  
Bond Formation ◽  
Cyclic Ketone ◽  
Cyclic Ketones ◽  
Carbon Bond ◽  
Carbon Carbon Bond

scholarly journals Organocatalysis for the Asymmetric Michael Addition of Cycloketones and α, β-Unsaturated Nitroalkenes

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1004
Author(s):  
Jae Ho Shim ◽  
Byung Kook Ahn ◽  
Ji Yeon Lee ◽  
Hyeon Soo Kim ◽  
Deok-Chan Ha
Keyword(s):  
Nitro Group ◽  
Michael Addition ◽  
Primary Amine ◽  
Bond Formation ◽  
Hydrogen Bond Formation ◽  
Carbon Bond ◽  
Chiral Diamine ◽  
Asymmetric Michael Addition ◽  
Carbon Carbon Bond ◽  
High Level

Michael addition is one of the most important carbon–carbon bond formation reactions. In this study, an (R, R)-1,2-diphenylethylenediamine (DPEN)-based thiourea organocatalyst was applied to the asymmetric Michael addition of nitroalkenes and cycloketones to produce a chiral product. The primary amine moiety in DPEN reacts with the ketone to form an enamine and is activated through the hydrogen bond formation between the nitro group in the α, β-unsaturated nitroalkene and thiourea. Here, the aim was to obtain an asymmetric Michael product through the 1,4-addition of the enamine to an alkene to form a new carbon–carbon bond. As a result, the primary amine of the chiral diamine was converted into an enamine. The reaction proceeded with a relatively high level of enantioselectivity achieved using double activation through the hydrogen bonding of the nitro group and thiourea. Michael products with high levels of enantioselectivity (76–99% syn ee) and diastereoselectivity (syn/anti = 9/1) were obtained with yields in the range of 88–99% depending on the ketone.

Ready Carbon-Carbon Bond Formation of 2-(Trifluoromethyl)acrylate via Michael Addition Reactions

1994 ◽  
Vol 59 (17) ◽  
pp. 5100-5103 ◽  
Author(s):  
Takashi Yamazaki ◽  
Shuichi Hiraoka ◽  
Tomoya Kitazume
Keyword(s):  
Michael Addition ◽  
Bond Formation ◽  
Addition Reactions ◽  
Carbon Bond ◽  
Carbon Carbon Bond

Carbon Dioxide-Mediated C(sp2)–H Arylation of Primary and Secondary Benzylamines

2018 ◽  
Author(s):  
Mohit Kapoor ◽  
Pratibha Chand-Thakuri ◽  
Michael Young
Keyword(s):  
Carbon Dioxide ◽  
Transition Metal ◽  
Bond Activation ◽  
Bond Formation ◽  
Carbon Bond ◽  
Chelate Effect ◽  
Free Amine ◽  
Carbon Carbon Bond ◽  
New Strategy ◽  
Metal Catalyzed

Carbon-carbon bond formation by transition metal-catalyzed C–H activation has become an important strategy to fabricate new bonds in a rapid fashion. Despite the pharmacological importance of <i>ortho</i>-arylbenzylamines, however, effective <i>ortho</i>-C–C bond formation from C–H bond activation of free primary and secondary benzylamines using Pd<sup>II</sup> remains an outstanding challenge. Presented herein is a new strategy for constructing <i>ortho</i>-arylated primary and secondary benzylamines mediated by carbon dioxide (CO<sub>2</sub>). The use of CO<sub>2</sub> is critical to allowing this transformation to proceed under milder conditions than previously reported, and that are necessary to furnish free amine products that can be directly used or elaborated without the need for deprotection. In cases where diarylation is possible, a chelate effect is demonstrated to facilitate selective monoarylation.

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