Lewis Acid Catalyzed Intramolecular [4+2] Cycloaddition of In Situ Generated Aza-Quinone Methides for the Stereoselective Synthesis of Furo/pyrano[3,2-c ]tetrahydroquinolines

2019 ◽  
Author(s):  
Santosh J. Gharpure ◽  
Dharmendra S. Vishwakarma
Keyword(s):  
Lewis Acid ◽  
Stereoselective Synthesis ◽  
Quinone Methides ◽  
Acid Catalyzed

Lewis acid-catalyzed tandem cyclization of in situ generated o-quinone methides and arylsulfonyl hydrazides for a one-pot entry to 3-sulfonylbenzofurans

2019 ◽  
Vol 6 (24) ◽  
pp. 3929-3933 ◽  
Author(s):  
Fan-Xiao Meng ◽  
Ruo-Nan Wang ◽  
Hong-Li Huang ◽  
Shu-Wen Gong ◽  
Qian-Li Li ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Quinone Methides ◽  
One Pot ◽  
Acid Catalyzed ◽  
Tandem Cyclization ◽  
First Time

Lewis acid-mediated one-pot tandem cyclization of o-QMs with arylsulfonyl hydrazides was described for the first time and the corresponding 3-sulfonylbenzofuran products were obtained in moderate to good yields.

Lewis Acid Catalyzed Tandem 1,4-Conjugate Addition/Cyclization of in Situ Generated Alkynyl o-Quinone Methides and Electron-Rich Phenols: Synthesis of Dioxabicyclo[3.3.1]nonane Skeletons

2018 ◽  
Vol 20 (14) ◽  
pp. 4371-4374 ◽  
Author(s):  
Ji-Yuan Du ◽  
Yan-Hua Ma ◽  
Fan-Xiao Meng ◽  
Bao-Li Chen ◽  
Shao-Liang Zhang ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
Acid Catalyzed

Catalytic Carbonyl-Olefin Metathesis of Aliphatic Ketones: Iron(III) HomoDimers as Lewis Acidic Superelectrophiles

2018 ◽  
Author(s):  
Haley Albright ◽  
Paul S. Riehl ◽  
Christopher C. McAtee ◽  
Jolene P. Reid ◽  
Jacob R. Ludwig ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Olefin Metathesis ◽  
Acid Activation ◽  
Lewis Acid Catalysts ◽  
Distinct Mode ◽  
Aliphatic Ketones ◽  
Carbon Carbon Bond ◽  
Metathesis Reactions ◽  
Acid Catalyzed

<div>Catalytic carbonyl-olefin metathesis reactions have recently been developed as a powerful tool for carbon-carbon bond</div><div>formation. However, currently available synthetic protocols rely exclusively on aryl ketone substrates while the corresponding aliphatic analogs remain elusive. We herein report the development of Lewis acid-catalyzed carbonyl-olefin ring-closing metathesis reactions for aliphatic ketones. Mechanistic investigations are consistent with a distinct mode of activation relying on the in situ formation of a homobimetallic singly-bridged iron(III)-dimer as the active catalytic species. These “superelectrophiles” function as more powerful Lewis acid catalysts that form upon association of individual iron(III)-monomers. While this mode of Lewis acid activation has previously been postulated to exist, it has not yet been applied in a catalytic setting. The insights presented are expected to enable further advancement in Lewis acid catalysis by building upon the activation principle of “superelectrophiles” and broaden the current scope of catalytic carbonyl-olefin metathesis reactions.</div>

Stereoselective Synthesis of C-Ketosides by Lewis Acid Catalyzed C-Glycosylation of Alkynyl-Ketoses.

ChemInform ◽  
2003 ◽  
Vol 34 (14) ◽  
Author(s):  
Ana M. Gomez ◽  
Clara Uriel ◽  
Serafin Valverde ◽  
Slawomir Jarosz ◽  
J. Cristobal Lopez
Keyword(s):  
Lewis Acid ◽  
Stereoselective Synthesis ◽  
Acid Catalyzed

Counterion effects in the catalytic stereoselective synthesis of 2,3′-pyrrolidinyl spirooxindoles

2014 ◽  
Vol 50 (40) ◽  
pp. 5242-5244 ◽  
Author(s):  
Jacob P. MacDonald ◽  
Benjamin H. Shupe ◽  
John D. Schreiber ◽  
Annaliese K. Franz
Keyword(s):  
Lewis Acid ◽  
Stereoselective Synthesis ◽  
Acid Catalyzed

A Lewis acid-catalyzed stereoselective [3+2] annulation of crotylsilanes with iminooxindoles is reported to access 2,3′-pyrrolidinyl spirooxindoles with four stereocenters.

scholarly journals A three-component, Zn(OTf)2-mediated entry into trisubstituted 2-aminoimidazoles

2019 ◽  
Vol 15 ◽  
pp. 1061-1064 ◽  
Author(s):  
Alexei Lukin ◽  
Anna Bakholdina ◽  
Anna Kryukova ◽  
Alexander Sapegin ◽  
Mikhail Krasavin
Keyword(s):  
Lewis Acid ◽  
Primary Amine ◽  
Three Component Reaction ◽  
Acid Catalyzed ◽  
In Situ Generation

A three-component reaction involving in situ generation of propargylureas and subsequent Zn(OTf)2-mediated cyclocondensation with a primary amine yielded trisubstituted 2-aminoimidazoles. These findings are in contrast to the previously reported base-promoted unimolecular cyclization of propargylureas (leading to 2-imidazolones) and extend the range of Lewis acid-catalyzed azole syntheses based on N-carbonyl propargylamines.

Intercepting the Nazarov Oxyallyl Intermediate with α-Formyl­vinyl Anion Equivalents to Access Formal Morita–Baylis–Hillman Alkylation Products

Synlett ◽  
2017 ◽  
Vol 28 (12) ◽  
pp. 1486-1490 ◽  
Author(s):  
F. West ◽  
Yen-Ku Wu ◽  
Rongrong Lin
Keyword(s):  
Lewis Acid ◽  
Stereoselective Synthesis ◽  
Domino Reaction ◽  
Alkylation Process ◽  
Acid Catalyzed

A Lewis acid catalyzed cationic domino reaction involving sequential electrocyclization and polar addition of allenol ethers onto the resulting oxyallyl species is described. The overall sequence allows a highly stereoselective synthesis of densely substituted cyclopentanoid compounds containing α-formylvinyl functionality which is formally equivalent to products of a Morita–Baylis–Hillman alkylation process.

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