scholarly journals Lewis Acid Promoted Trapping of Chiral Aza-enolates

Synthesis ◽  
2019 ◽  
Vol 51 (05) ◽  
pp. 1253-1262
Author(s):  
Francesco Lanza ◽  
Juana Pérez ◽  
Ravindra Jumde ◽  
Syuzanna Harutyunyan
Keyword(s):  
Lewis Acid ◽  
Conjugate Addition ◽  
Conventional Wisdom ◽  
Grignard Reagents ◽  
One Pot ◽  
Michael Acceptor ◽  
Michael Acceptors ◽  
Reactivity Order

We present a study on sequential conjugate addition of ­Grignard reagents to alkenyl-heteroarenes followed by trapping of the resulting enolates, yielding moderate to good diastereoselectivities. Contrary to conventional wisdom, one-pot conjugate addition/trapping using two reactive Michael acceptors in combination with Grignard reagents can proceed via conjugate addition to the least reactive Michael acceptor. This unusual chemoselectivity is triggered by the presence of a Lewis acid, reverting the usual reactivity order of Michael acceptors.

scholarly journals Trapping of chiral enolates generated by Lewis acid promoted conjugate addition of Grignard reagents to unreactive Michael acceptors by various electrophiles

2019 ◽  
Vol 55 (78) ◽  
pp. 11766-11769
Author(s):  
Denisa Vargová ◽  
Juana M. Pérez ◽  
Syuzanna R. Harutyunyan ◽  
Radovan Šebesta
Keyword(s):  
Carboxylic Acids ◽  
Lewis Acid ◽  
Conjugate Addition ◽  
Grignard Reagents ◽  
Michael Acceptors ◽  
Chiral Enolates

Chiral enolates generated by asymmetric Cu-catalyzed and Lewis acid promoted conjugate addition of Grignard reagents to unsaturated amides, alkenylheterocycles, and carboxylic acids are trapped with cations, activated alkenes, or bromine.

ChemInform Abstract: Enantioselective One-Pot Conjugate Addition of Grignard Reagents to Cyclic Enones Followed by Amidomethylation.

ChemInform ◽  
2012 ◽  
Vol 43 (18) ◽  
pp. no-no
Author(s):  
Filip Bilcik ◽  
Michal Drusan ◽  
Jozef Marak ◽  
Radovan Sebesta
Keyword(s):  
Conjugate Addition ◽  
Grignard Reagents ◽  
One Pot ◽  
Cyclic Enones

scholarly journals Preparation of spiro[indole-3,5′-isoxazoles] via Grignard conjugate addition/spirocyclization sequence

RSC Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 1783-1793
Author(s):  
Alexander V. Aksenov ◽  
Dmitrii A. Aksenov ◽  
Nicolai A. Aksenov ◽  
Anton A. Skomorokhov ◽  
Elena V. Aleksandrova ◽  
...  
Keyword(s):  
Conjugate Addition ◽  
Grignard Reagents ◽  
One Pot ◽  
Subsequent Acid

One-pot procedure combining conjugate addition of Grignard reagents to (2-nitroalkenyl)indoles and subsequent acid-assisted spirocyclization allowed for diastereoselective preparation of 4′H-spiro[indole-3,5′-isoxazoles].

Enantioselective One-Pot Conjugate Addition of Grignard Reagents to Cyclic Enones Followed by Amidomethylation

2011 ◽  
Vol 77 (1) ◽  
pp. 760-765 ◽  
Author(s):  
Filip Bilčík ◽  
Michal Drusan ◽  
Jozef Marák ◽  
Radovan Šebesta
Keyword(s):  
Conjugate Addition ◽  
Grignard Reagents ◽  
One Pot ◽  
Cyclic Enones

Catalytic asymmetric conjugate addition of isocyanoacetate to (Z)-3-substituted-2-(4-pyridyl)-acrylonitrile, a reactive class of Michael acceptor

2016 ◽  
Vol 52 (8) ◽  
pp. 1697-1700 ◽  
Author(s):  
Claudia Del Fiandra ◽  
Maria Moccia ◽  
Valentina Cerulli ◽  
Mauro F. A. Adamo
Keyword(s):  
Ethyl Ester ◽  
Quaternary Ammonium ◽  
Conjugate Addition ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Michael Acceptor ◽  
Michael Acceptors ◽  
Catalytic Asymmetric

Un-substituted isocyanoacetate ethyl ester reacted with Michael acceptors 1a–m under the catalysis of Cinchona based quaternary ammonium salts providing imines 4a–m as a single diastereoisomer and in up to 94% ees.

Enantioselective One-Pot Conjugate Addition of Grignard Reagents Followed by a Mannich Reaction

2010 ◽  
Vol 2010 (29) ◽  
pp. 5666-5671 ◽  
Author(s):  
Radovan Šebesta ◽  
Filip Bilčík ◽  
Peter Fodran
Keyword(s):  
Mannich Reaction ◽  
Conjugate Addition ◽  
Grignard Reagents ◽  
One Pot
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