ChemInform Abstract: ON THE REACTION OF PHENYLDISIC ACIDS WITH α,β-UNSATURATED CARBONYL COMPOUNDS. REVERSIBLE NONCATALYZED MICHAEL ADDITION AND RING CLOSURE TO DERIVATIVES OF 2H,7H-ISOXAZOLO(3,2-B)(1,3)OXAZINE

1980 ◽  
Vol 11 (35) ◽  
Author(s):  
G. ZVILICHOVSKY ◽  
M. DAVID ◽  
E. NEMES
Keyword(s):  
Michael Addition ◽  
Carbonyl Compounds ◽  
Ring Closure ◽  
Derivatives Of

scholarly journals Nucleofugal behavior of a β-shielded α-cyanovinyl carbanion

2018 ◽  
Vol 14 ◽  
pp. 3018-3024
Author(s):  
Rudolf Knorr ◽  
Barbara Schmidt
Keyword(s):  
Michael Addition ◽  
Carbonyl Compounds ◽  
Room Temperature ◽  
Experimental Conditions ◽  
Metal Free ◽  
Metal Derivatives ◽  
Carbonyl Addition ◽  
Derivatives Of

Sterically well-shielded against unsolicited Michael addition and polymerization reactions, α-metalated α-(1,1,3,3-tetramethylindan-2-ylidene)acetonitriles added reversibly to three small aldehydes and two bulky ketones at room temperature. Experimental conditions were determined for transfer of the nucleofugal title carbanion unit between different carbonyl compounds. These readily occurring retro-additions via C–C(O) bond fission may also be used to generate different metal derivatives of the nucleofugal anions as equilibrium components. Fluoride-catalyzed, metal-free desilylation admitted carbonyl addition but blocked the retro-addition.

Synthesis of azaanthraquinones: homolytic substitution of pyridines

1982 ◽  
Vol 35 (7) ◽  
pp. 1451 ◽  
Author(s):  
DW Cameron ◽  
KR Deutscher ◽  
GI Feutrill ◽  
DE Hunt
Keyword(s):  
Ring Closure ◽  
Pyridine Derivatives ◽  
Derivatives Of ◽  
Substituted 1 ◽  
Homolytic Substitution

Synthesis of specific di- and tri-hydroxyazaanthraquinones by Friedel-Crafts procedures is limited by orientational ambiguity and by the lack of reactivity of pyridine derivatives in electrophilic acylation processes; however, suitable pyridines have been made to undergo radical benzoylation and benzylation at unsubstituted positions 2, 4 and 6. In particular, derivatives of pyridine-3-carbo-nitrile have been benzoylated at positions 2 and 4. Ring closure by intramolecular Houben-Hoesch reaction has then led to specifically substituted 1-and 2-azaanthraquinones and thence to the antibiotic bostrycoidin (1).

Catalyst-Free One-Pot Synthesis of Novel Heteroarylamine Substituted Furo[3,2-c]coumarins

Synlett ◽  
2018 ◽  
Vol 29 (12) ◽  
pp. 1589-1592 ◽  
Author(s):  
Abolfazl Olyaei ◽  
Mahnaz Saraei ◽  
Reyhaneh Khoeiniha
Keyword(s):  
Michael Addition ◽  
Aldol Condensation ◽  
Ring Closure ◽  
Dehydration Reaction ◽  
One Pot ◽  
Catalyst Free ◽  
One Pot Synthesis ◽  
Tandem Process ◽  
First Time

A high-yielding cyclocondensation of 4-hydroxycoumarin, phenylglyoxal monohydrate, and heteroarylamines proceeds without catalysis, which gives novel functionalized furo[3,2-c]coumarins and heteroarylamino alkylation of coumarin products in acetonitrile under reflux, is reported for the first time. This tandem process involves sequentially an aldol condensation, Michael addition, a ring closure, and dehydration reaction.

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