The Wittig Reaction of 2-t-Butoxycarbonyl-1-methoxycarbonylethylidenetriphenylphosphorane: A Surrogate for the Stobbe Reaction

1987 ◽  
Vol 40 (10) ◽  
pp. 1737 ◽  
Author(s):  
MA Rizzacasa ◽  
MV Sargent
Keyword(s):  
Wittig Reaction ◽  
Aromatic Aldehydes ◽  
High Yield

The reaction of 2-t-butoxycarbonyl-l-methoxycarbonylethylidenetriphenylphosphorane (3) with a range of aromatic aldehydes has been explored. The resultant itaconic esters, obtained in high yield, are readily converted into methyl 4-acetoxynaphthalene-2-carboxylates.

Visible Light Assisted Hantzsch Reaction: Synthesis of Polycyclic Dihydropyridines

2019 ◽  
Vol 16 (8) ◽  
pp. 676-682
Author(s):  
Ankusab Noorahmadsab Nadaf ◽  
Kalegowda Shivashankar
Keyword(s):  
Reaction Time ◽  
Light Intensity ◽  
Ammonium Acetate ◽  
Low Cost ◽  
Aromatic Aldehydes ◽  
Light Irradiation ◽  
High Yield ◽  
Short Reaction Time ◽  
Green Protocol ◽  
Dihydropyridine Derivatives

The polycyclic dihydropyridine nucleus represents the heterocyclic system of invaluable core motifs with wide applications in chemical, biological and physical properties. Although this kind of compounds have been extensively synthesized by other groups, the synthesis of these compounds under CFL light intensity were not explored. The synthesis of polycyclic dihydropyridine derivatives were achieved through the reaction of 4-hydroxycoumarin, aromatic aldehydes and ammonium acetate under CFL light irradiation conditions. A series of polycyclic dihydropyridine derivatives were prepared under CFL light irradiation conditions with high yield, short reaction time, ambient condition and without the use of catalyst. The results displayed an efficient method for the synthesis of polycyclic dihydropyridine derivatives. Clean profile, short reaction time, low cost and use of CFL light intensity instead of catalyst making it a genuinely green protocol.

An easy approach to dihydrochalcones via chalcone in situ hydrogenation

2016 ◽  
Vol 88 (4) ◽  
pp. 349-361 ◽  
Author(s):  
Ana R. Jesus ◽  
Ana P. Marques ◽  
Amélia P. Rauter
Keyword(s):  
Room Temperature ◽  
Aromatic Aldehydes ◽  
Iron Chloride ◽  
High Yield ◽  
Microwave Assisted ◽  
Olefinic Double Bond ◽  
Single Reaction Product ◽  
Very High ◽  
Single Reaction

AbstractDihydrochalcones are polyphenols that exhibit a diversity of bioactivities, namely anti-inflammatory, antimicrobial and antiviral. We have explored the synthetic access to such molecular entities, and describe now an easy and scalable approach based on reduction of the olefinic double bond of chalcone precursors via in situ hydrogenation with the system Et3SiH-Pd/C in very high yield. The intermediate chalcones were synthesized also by a simple and efficient microwave-assisted Claisen–Schmidt condensation of aromatic aldehydes with acetophenones, conveniently protected with ethoxymethyl ether, if required. Chalcones were obtained as single reaction product in high yield in 2–3 h, while under conventional conditions at room temperature the reaction was carried out with completion only after 24 h. In addition, microwave irradiation has proven very efficient for deprotection of ethoxymethyl ether with iron chloride in only 10 min and very high yield.

scholarly journals A Facile Solvent Free Synthesis of 3-arylidenechroman-4-ones Using Grinding Technique

2012 ◽  
Vol 9 (3) ◽  
pp. 1251-1256 ◽  
Author(s):  
Suresh Kumar ◽  
Jagdish K. Makrandi
Keyword(s):  
Polyphosphoric Acid ◽  
Cold Water ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Environmentally Benign ◽  
High Yield ◽  
Solvent Free Conditions ◽  
Microwave Irradiations ◽  
Grinding Technique ◽  
Solvent Free Synthesis

An efficient method for the synthesis of 3-arylidenechroman-4-ones has been developed under solvent free conditions using grinding technique. Grinding of variously substituted chroman-4-ones with aromatic aldehydes in presence of anhydrous barium hydroxide at room temperature give 3-arylidenechroman-4-ones in high yield (75-92%). Products are obtained by just acidification of the reaction mixture in ice cold water. Reaction in solid state, with enhanced rate, high selectivity and manipulative simplicity are the attractive features of this environmentally benign protocol. The chroman-4-one derivatives required for the reaction have been obtained by polyphosphoric acid (PPA) catalysed cyclisation of phenoxypropanoic acids under microwave irradiations.

scholarly journals Facile Condensation of Aromatic Aldehydes with Chroman-4-ones and 1-Thiochroman-4-ones Catalysed by Amberlyst-15 under Microwave Irradiation Condition

2011 ◽  
Vol 8 (2) ◽  
pp. 863-869 ◽  
Author(s):  
Tapas K. Mandal ◽  
Rammohan Pal ◽  
Rina Mondal ◽  
Asok K. Mallik
Keyword(s):  
Microwave Irradiation ◽  
Aldol Condensation ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Environmentally Benign ◽  
High Yield ◽  
Irradiation Condition ◽  
Free Condition ◽  
Amberlyst 15 ◽  
Solvent Free Condition

Different aromatic aldehydes and cinnamaldehyde undergo cross-aldol condensation with chroman-4-ones and1-thiochroman-4-ones in the presence of amberlyst-15 under microwave irradiation in solvent free condition to afford rapidly the correspondingE-3-arylidene andE-3-cinnamylidene derivatives, respectively, in high yield. This process is simple, efficient and environmentally benign.

An Atom-economic Efficient Synthesis of 1-Amidoalkyl-2-naphthols Mediated By Hexachlorocyclotriphosphazene (HCCP) as a Novel Catalyst

2019 ◽  
Vol 16 (10) ◽  
pp. 846-850 ◽  
Author(s):  
Rajesh K. Singh ◽  
Shallu Chaudhary ◽  
D.N. Prasad ◽  
Sahil Kumar
Keyword(s):  
Microwave Irradiation ◽  
Aromatic Aldehydes ◽  
High Yield ◽  
Efficient Synthesis ◽  
Hot Plate ◽  
One Pot ◽  
Plate Heating ◽  
Novel Catalyst ◽  
Thermal Technique ◽  
Naphthol Derivatives

A multicomponent one-pot atom-economic reaction is performed for an efficient synthesis of 1-amidoalkyl-2-naphthol from aromatic aldehydes, β-naphthol and amide/urea promoted by hexachlorocyclotriphosphazene (HCCP). Various techniques such as stirring, microwave irradiation and thermal technique (hot plate and oil bath) were used in different solvents for the synthesis of 1- amidoalkyl-2-naphthol derivatives with moderate to excellent yield. Among the four methods, microwave irradiation and oil bath heating provide high yield as compared to the hot plate heating and stirring method. The low yield may be due to the formation of undesired side-products due to non-uniform heating.

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