In situ generation of less accessible Boc-imines from aldehydes: construction of a quaternary carbon by the Mannich reaction or unprecedented aldol reaction

2017 ◽  
Vol 15 (21) ◽  
pp. 4527-4530 ◽  
Author(s):  
Taichi Kano ◽  
Chihiro Homma ◽  
Keiji Maruoka
Keyword(s):  
Mannich Reaction ◽  
Aldol Reaction ◽  
Quaternary Carbon ◽  
Mannich Reactions ◽  
The Mannich Reaction ◽  
In Situ Generation

Mannich reactions of β-dicarbonyls with in situ generated less accessible Boc-imines from aldehydes were achieved.

New tartrate based cyclic phosphoric acids as organocatalysts in Mannich reactions

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Tuvshinjargal Budragchaa ◽  
Michael Abraham ◽  
Wolfgang Schöfberger ◽  
Alexander Roller ◽  
Michael Widhalm
Keyword(s):  
Crystal Structure ◽  
Dft Calculations ◽  
Structure Analysis ◽  
Mannich Reaction ◽  
Structural Variation ◽  
Crystal Structure Analysis ◽  
Mannich Reactions ◽  
Optimization Study ◽  
The Mannich Reaction ◽  
Phosphoric Acids

Abstract Cyclic phosphoric acids have attracted much attention as chiral organocatalysts. While binaphthol based ligands have been extensively used in various transformations, the analogous TADDOL-type ligands are less explored. A library of seventeen cyclic phosphoric acids with structural variation of the TADDOL backbone were synthesized and an optimization study of the Mannich reaction of aromatic N-(2-hydroxyphenyl)imines with 2,2-dimethyl-1-methoxy-silylenolate was performed. Enantioselectivities between 96% (S) and 70% (R) were observed and a rationalisation, based on crystal structure analysis and DFT calculations, is provided.

scholarly journals Three-component radical homo Mannich reaction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shuai Shi ◽  
Wenting Qiu ◽  
Pannan Miao ◽  
Ruining Li ◽  
Xianfeng Lin ◽  
...  
Keyword(s):  
Mannich Reaction ◽  
Aliphatic Amine ◽  
Single Step ◽  
Great Utility ◽  
Powerful Approach ◽  
Desulfurization Process ◽  
Ionic Nature ◽  
The Mannich Reaction ◽  
Pharmaceutical Agents

AbstractAliphatic amine, especially tertiary aliphatic amine, is one of the most popular functionalities found in pharmaceutical agents. The Mannich reaction is a classical and widely used transformation for the synthesis of β-amino-carbonyl products. Due to an ionic nature of the mechanism, the Mannich reaction can only use non-enolizable aldehydes as substrates, which significantly limits the further applications of this powerful approach. Here we show, by employing a radical process, we are able to utilize enolizable aldehydes as substrates and develop the three-component radical homo Mannich reaction for the streamlined synthesis of γ-amino-carbonyl compounds. The electrophilic radicals are generated from thiols via the desulfurization process facilitated by visible-light, and then add to the electron-rich double bonds of the in-situ formed enamines to provide the products in a single step. The broad scope, mild conditions, high functional group tolerance, and modularity of this metal-free approach for the synthesis of complex tertiary amine scaffolds will likely be of great utility to chemists in both academia and industry.

In situ generation of N-Boc-protected alkenyl imines: controlling the E/Z geometry of alkenyl moieties in the Mukaiyama–Mannich reaction

2017 ◽  
Vol 53 (58) ◽  
pp. 8203-8206 ◽  
Author(s):  
Jian-Fei Bai ◽  
Hajime Sasagawa ◽  
Taiga Yurino ◽  
Taichi Kano ◽  
Keiji Maruoka
Keyword(s):  
Mannich Reaction ◽  
Acidic Conditions ◽  
In Situ Generation

Readily available Boc-protected Z-alkenyl aminals were used as Z-alkenyl and E-alkenyl imine precursors under acidic conditions. In the Mukaiyama–Mannich reaction of Z-alkenyl Boc-aminals, the E/Z geometry of the products was controlled by the catalyst used.

MCM-41-Supported Linear Alkylamine-Catalyzed In Situ Generation of Unstable Trifluoroacetaldehyde and Successive syn -Selective Direct Aldol Reaction with Cyclic Ketones

2017 ◽  
Vol 2 (23) ◽  
pp. 6673-6682
Author(s):  
Kazumasa Funabiki ◽  
Hideyuki Nagaya ◽  
Hiroshi Gonda ◽  
Yuta Sakaida ◽  
Yasuhiro Kubota ◽  
...  
Keyword(s):  
Aldol Reaction ◽  
Cyclic Ketones ◽  
Direct Aldol Reaction ◽  
In Situ Generation ◽  
Mcm 41

Detrifluoroacetylative in Situ Generation of Free 3-Fluoroindolin-2-one-Derived Tertiary Enolates: Design, Synthesis, and Assessment of Reactivity toward Asymmetric Mannich Reactions

2016 ◽  
Vol 18 (13) ◽  
pp. 3270-3273 ◽  
Author(s):  
Chen Xie ◽  
Lijun Zhang ◽  
Wanxing Sha ◽  
Vadim A. Soloshonok ◽  
Jianlin Han ◽  
...  
Keyword(s):  
Mannich Reactions ◽  
Design Synthesis ◽  
In Situ Generation
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