Stereoselective Alkylation of Indole with 5-Arylidene-Meldrum’s Acids in the Presence of Organocatalysts

2018 ◽  
Vol 15 (10) ◽  
pp. 883-890
Author(s):  
Ewelina Najda-Mocarska ◽  
Anna Zakaszewska ◽  
Karolina Janikowska ◽  
Slawomir Makowiec
Keyword(s):  
Meldrum's Acids

Synthesis of Heterocycles Using Acyl Meldrum's Acids. Reactions with Aromatic Hydroxylamines

Heterocycles ◽  
1981 ◽  
Vol 16 (1) ◽  
pp. 177 ◽  
Author(s):  
Kunihiko Mohri ◽  
Yuji Oikawa ◽  
Ken-ichi Hirao ◽  
Osamu Yonemitsu
Keyword(s):  
Meldrum's Acids

Benzhydrylium and tritylium ions: complementary probes for examining ambident nucleophiles

2015 ◽  
Vol 87 (4) ◽  
pp. 341-351 ◽  
Author(s):  
Armin R. Ofial
Keyword(s):  
Free Energy ◽  
Rate Constants ◽  
The Other ◽  
Steric Effects ◽  
Linear Free Energy Relationship ◽  
Reliable Tool ◽  
Linear Free Energy ◽  
Sensitivity Parameter ◽  
Meldrum's Acids ◽  
Kinetics Of

AbstractThe linear free energy relationship log k = sN(N + E) (eq. 1), in which E is an electrophilicity, N is a nucleophilicity, and sN is a nucleophile-dependent sensitivity parameter, is a reliable tool for predicting rate constants of bimolecular electrophile-nucleophile combinations. Nucleophilicity scales that are based on eq. (1) rely on a set of structurally similar benzhydrylium ions (Ar2CH+) as reference electrophiles. As steric effects are not explicitely considered, eq. (1) cannot unrestrictedly be employed for reactions of bulky substrates. Since, on the other hand, the reactions of tritylium ions (Ar3C+) with hydride donors, alcohols, and amines were found to follow eq. (1), tritylium ions turned out to be complementary tools for probing organic reactivity. Kinetics of the reactions of Ar3C+ with π-nucleophiles (olefins), n-nucleophiles (amines, alcohols, water), hydride donors and ambident nucleophiles, such as the anions of 5-substituted Meldrum’s acids, are discussed to analyze the applicability of tritylium ions as reference electrophiles.

Yb(OTf)3-Catalyzed Reactions of 5-Alkylidene Meldrum's Acids with Phenols:  One-Pot Assembly of 3,4-Dihydrocoumarins, 4-Chromanones, Coumarins, and Chromones

2006 ◽  
Vol 71 (1) ◽  
pp. 409-412 ◽  
Author(s):  
Eric Fillion ◽  
Aaron M. Dumas ◽  
Bryan A. Kuropatwa ◽  
Neil R. Malhotra ◽  
Tamsyn C. Sitler
Keyword(s):  
One Pot ◽  
Meldrum's Acids ◽  
Catalyzed Reactions

Modular Synthesis of Tetrahydrofluorenones from 5-Alkylidene Meldrum's Acids

2006 ◽  
Vol 71 (26) ◽  
pp. 9899-9902 ◽  
Author(s):  
Eric Fillion ◽  
Aaron M. Dumas ◽  
Sylvia A. Hogg
Keyword(s):  
Modular Synthesis ◽  
Meldrum's Acids

A general and practical preparation of alkylidene Meldrum’s acids

2007 ◽  
Vol 48 (40) ◽  
pp. 7072-7074 ◽  
Author(s):  
Aaron M. Dumas ◽  
Adam Seed ◽  
Alexander K. Zorzitto ◽  
Eric Fillion
Keyword(s):  
Meldrum's Acids

The stereoselective formation of β-lactams with acyl ketenes generated from 5-acyl-Meldrum's acids

2016 ◽  
Vol 40 (8) ◽  
pp. 6546-6549 ◽  
Author(s):  
Anna Zakaszewska ◽  
Ewelina Najda ◽  
Sławomir Makowiec
Keyword(s):  
Thermal Decomposition ◽  
Meldrum's Acids

Acyl ketenes formed during thermal decomposition of 5-acyl-2,2-dimethyl-1,3-dioxa-4,6-diones undergo stereoselective [2+2] cycloaddition to chiral aldimines.

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