Organic Chemistry Archive
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Multicomponent Reactions
Posted on January 28, 2011 | 1 CommentMulticomponent reactions (MCRs) are highly convergent reactions, with high atom efficiency, good bond forming capabilities and higher yields in comparison to a similar multistep reaction. -
Malonic Ester Synthesis – Alkylation of Enolates
Posted on February 6, 2011 | No CommentsMalonic esters when reacted with alkyl halide (R-X) in the presence of base such as NaOH will produce ?-alkylated esters. However, reaction will not stop there. Over time, the reaction will also give disubstituted products as well as free acids. -
Acetoacetic Ester Synthesis – Alkylation of Enolates
Posted on February 8, 2011 | No CommentsAcetoacetic ester synthesis is similar to malonic ester synthesis.When ?-keto ester is reacted with a weak base such as Sodium Hydroxide (NaOH) in the presence of alkyl halide (R-X), it produces ?-alkylated ?-keto esters and also di-alkylated products. However, upon acidification the mixture will lose a molecule of carbon dioxide to get decarboxylated to give ketones as well. This will be further explained with the mechanism. -
Using the non-selective nature of acetoacetic ester synthesis and malonic ester synthesis to produce cyclic compounds
Posted on February 9, 2011 | 2 CommentsAs has been discussed previously - acetoacetic ester synthesis and malonic ester synthesis are non-selective, in that, they can produce dialkylated products. This particular property of these reactions can be made use of to synthesize cyclic compounds using a alkyl dihalide. -
Chemistry of Enolates and Enols – Acidity of Alpha-Hydrogens
Posted on February 13, 2011 | 10 CommentsIn the presence of carbonyl functional group, the alpha-hydrogens of a molecule exhibit acidity i.e. in the presence of a base they can be abstracted very easily to yield a carbanion. The carbanion can be stabilized either with resonance to yield enolates. -
Catalytic Azide-Alkyne Cycloaddition: Reactivity and Application
Posted on February 15, 2011 | No CommentsCopper catalyzed alkyne-azide cycloaddition (CuAAC) is one of the most reliable click reaction that has enabled the practical and efficient preparation of 1,4-disubstituted 1,2,3 triazoles from a wide range of substituted alkynes and azides which cannot be typically attained by the traditional Huisgen thermal cycloaddition reaction -
Chemistry of Enolates – C vs O Alkylation
Posted on February 25, 2011 | No CommentsEnolates can be very tricky to handle. Upon reaction with a base and in the presence of alkyl halide, the carbonyl compounds with ?-hydrogens can undergo a reaction to produce a mixture of c-alkylated product or o-alkylated product. -
Thermodynamic Product vs Kinetic Product – with example of enolate formation of 2-methylcyclohexanone
Posted on March 13, 2011 | 3 CommentsA chemical reaction in which more than one product can be formed is generally governed by either laws of thermodynamics or kinetics. It can therefore yield either thermodynamic products or kinetic products. -
Phenolates- O-alkylation and C-alkylation
Posted on April 9, 2011 | No CommentsPhenolates are formed when a phenolic hydroxy group is reacted in the presence of base. The phenolate anion can react with alkyl halides to produce either O-alkylated or C-alkylated products. -
Imines and Enamines – Nitrogen Analogs of Enols and Enolates
Posted on April 12, 2011 | No CommentsWhen a carbonyl containing compound (such as aldehydes and ketones) reacts with an amine (primary, secondary or ammonia), it yields the formation of imines which in turn get converted to enamines. -
Producing and Using Imines and Enamines
Posted on April 19, 2011 | No CommentsImines and enamines are good substitutes for enols. However, it is important to note how to convert the carbonyl compounds into these enamines and imines. -
Michael Addition
Posted on April 24, 2011 | No CommentsMichael addition is a great tool which can be used by organic chemists to form new carbon-carbon bonds and increase the size of molecules. -
Aldol Condensation – Base Catalyzed
Posted on June 26, 2011 | No CommentsAldol condensation reaction can be either acid catalyzed or base catalyzed. In this reaction aldehydes (or carbonyl compounds) yield aldols (or ketols) which finally dehydrate to give alpha,beta-unsaturated compounds. -
Aldol Condensation – Acid Catalyzed
Posted on June 29, 2011 | No CommentsAldol condensation reaction can be either acid catalyzed or base catalyzed. This page deals with the acid catalysis mechanism of the aldol reaction. -
Directed Aldol Synthesis: Part 1 – Formation of E-Enolate and Z-Enolate
Posted on August 2, 2011 | 1 CommentAldol synthesis gives rise to stereocenters in the molecule. Directed aldol synthesis is an approach in order to control the stereochemistry of the product being formed. Formation of the enolate is the first step in aldol synthesis, and hence stereocontrol must begin with the first step itself. -
Directed Aldol Synthesis: Part 2 – Syn and Anti control using Zimmerman Traxler principle
Posted on August 3, 2011 | No CommentsAldol synthesis gives rise to stereocenters in the molecule. Directed aldol synthesis is an approach in order to control the stereochemistry of the product being formed. Part 2 considers how to control whether syn products or whether anti products are formed utilizing the Zimmerman Traxler principle of stereocontrol. -
Boron Enolates for Aldol Synthesis and Other Reactions
Posted on August 22, 2011 | No CommentsPreparation of boron enolates offers an advantage of obtaining highly selective enolate to control aldol condensation.