ppt
... Alkyl ammonium ions, R3NH+ X-, have pKa values in the range of 10-11 (ammonium ion, H4N+ X-, has a pKa ~ 9.3) The ammonium ions of aryl amines and heterocyclic aromatic amines are considerably more acidic than alkyl amines (pKa < 5). The nitrogen lone pair is less basic if it is in an sp2 hybridized ...
... Alkyl ammonium ions, R3NH+ X-, have pKa values in the range of 10-11 (ammonium ion, H4N+ X-, has a pKa ~ 9.3) The ammonium ions of aryl amines and heterocyclic aromatic amines are considerably more acidic than alkyl amines (pKa < 5). The nitrogen lone pair is less basic if it is in an sp2 hybridized ...
using hydrogen as a nucleophile in hydride reductions
... that taking place with carbonyl compounds, except that acid chlorides and esters have a leaving group (–Cl and –OR). So the reaction does not stop at formation of the alkoxide ion as a tetrahedral intermediate, but keeps going with an internal nucleophilic displacement of the leaving group. The dire ...
... that taking place with carbonyl compounds, except that acid chlorides and esters have a leaving group (–Cl and –OR). So the reaction does not stop at formation of the alkoxide ion as a tetrahedral intermediate, but keeps going with an internal nucleophilic displacement of the leaving group. The dire ...
104 Chapter 22: Amines. Organic derivatives of ammonia, NH3
... Alkyl ammonium ions, R3NH+ X-, have pKa values in the range of 10-11 (ammonium ion, H4N+ X-, has a pKa ~ 9.3) The ammonium ions of aryl amines and heterocyclic aromatic amines are considerably more acidic than alkyl amines (pKa < 5). The nitrogen lone pair is less basic if it is in an sp2 hybridized ...
... Alkyl ammonium ions, R3NH+ X-, have pKa values in the range of 10-11 (ammonium ion, H4N+ X-, has a pKa ~ 9.3) The ammonium ions of aryl amines and heterocyclic aromatic amines are considerably more acidic than alkyl amines (pKa < 5). The nitrogen lone pair is less basic if it is in an sp2 hybridized ...
CH2C05/ PH2C05/ PO2C05 COORDINATION CHEMISTRY
... How will you distinguish between singlet and triplet carbenes based on their stability and stereochemical bahaviour in addition reactions? Amination of haloarenes show high preferences in orientation. Explain with examples. Explain the structure and stability of carbon free radicals. What is auto-ox ...
... How will you distinguish between singlet and triplet carbenes based on their stability and stereochemical bahaviour in addition reactions? Amination of haloarenes show high preferences in orientation. Explain with examples. Explain the structure and stability of carbon free radicals. What is auto-ox ...
Organic Chemistry Fifth Edition
... group. More substituted carbon (more positive charge although more sterically hindered) is attacked by a weak nucleophile. Very similar to opening of cyclic bromonium ion. Review that subject. Due to resonance, some positive charge is located on this carbon. ...
... group. More substituted carbon (more positive charge although more sterically hindered) is attacked by a weak nucleophile. Very similar to opening of cyclic bromonium ion. Review that subject. Due to resonance, some positive charge is located on this carbon. ...
Carboxylic Acids
... The mechanism for nucleophilic acyl substitution varies depending if it occurs under acidic or basic conditions (similar to acid and base varieties of nucleophilic addition to aldehydes/ketones). Under basic conditions, a strong nucleophile can attack the carbonyl carbon, thus generating a tetrahed ...
... The mechanism for nucleophilic acyl substitution varies depending if it occurs under acidic or basic conditions (similar to acid and base varieties of nucleophilic addition to aldehydes/ketones). Under basic conditions, a strong nucleophile can attack the carbonyl carbon, thus generating a tetrahed ...
Topic 16 notes - A
... R-CHO + [O] R-COOH The most important difference in the reactions of aldehydes and ketones is the fact that aldehydes can be readily oxidized to carboxylic acids but ketones are not readily oxidized. This is used as the basis for two important distinguishing tests between aldehydes and ketones. Am ...
... R-CHO + [O] R-COOH The most important difference in the reactions of aldehydes and ketones is the fact that aldehydes can be readily oxidized to carboxylic acids but ketones are not readily oxidized. This is used as the basis for two important distinguishing tests between aldehydes and ketones. Am ...
10.4 Alcohols 10.4 Alcohols
... •The physical properties of alcohols are similar to those of both water and hydrocarbons •The shorter chain alcohols such as methanol and ethanol are similar to water, in general they •have higher boiling points than hydrocarbons but lower than water •dissolve in water to some degree •are more polar ...
... •The physical properties of alcohols are similar to those of both water and hydrocarbons •The shorter chain alcohols such as methanol and ethanol are similar to water, in general they •have higher boiling points than hydrocarbons but lower than water •dissolve in water to some degree •are more polar ...
synthesis, chemistry and optical resol
... products, alcohols 15c and 15b, after addition of chiral shift reagent, Eu(facam)3.22" The carbinyl carbons (6 69.39 and 69.42) were thereby split into two closely spaced peaks with relative areas of 35:31 and 127:109, respectively (A6 = 3.77 and 3.74, AA6 = 0.27 and 0.24).22b The same splitting wer ...
... products, alcohols 15c and 15b, after addition of chiral shift reagent, Eu(facam)3.22" The carbinyl carbons (6 69.39 and 69.42) were thereby split into two closely spaced peaks with relative areas of 35:31 and 127:109, respectively (A6 = 3.77 and 3.74, AA6 = 0.27 and 0.24).22b The same splitting wer ...
Rutgers...Ch17 Reactions of Aromatic Compounds
... Bromine itself is not electrophilic enough to react with benzene. But the addition of a strong Lewis acid (electron pair acceptor), such as FeBr3, catalyses the reaction, and leads to the substitution product. The bromine molecule reacts with FeBr3 by donating a pair of its electrons to the Lewis ac ...
... Bromine itself is not electrophilic enough to react with benzene. But the addition of a strong Lewis acid (electron pair acceptor), such as FeBr3, catalyses the reaction, and leads to the substitution product. The bromine molecule reacts with FeBr3 by donating a pair of its electrons to the Lewis ac ...
A Direct Access to 3-(2-Oxoalkyl)indoles via
... Madelung cyclization of N-acyl-o-toluidines are used very often. While a number of methods are available for the synthesis of 3-alkyl-substituted indoles,6,7 only a few are known for the synthesis of 3-(2-oxoalkyl)indoles. These includes (a) the alkylation of indole with R-diazocarbonyl compounds8a, ...
... Madelung cyclization of N-acyl-o-toluidines are used very often. While a number of methods are available for the synthesis of 3-alkyl-substituted indoles,6,7 only a few are known for the synthesis of 3-(2-oxoalkyl)indoles. These includes (a) the alkylation of indole with R-diazocarbonyl compounds8a, ...
A mechanistic approach to solvolysis of n-caproyl chloride (n
... There is a gradual increase in the enthalpy of activation with increase in bulkness of the alkyl group, which may be due to steric factor. However low enthalpy of activation in all cases disfavours SN1 mechanism. Involvement of addition ionization mechanism along with SN2 may be another factor which ...
... There is a gradual increase in the enthalpy of activation with increase in bulkness of the alkyl group, which may be due to steric factor. However low enthalpy of activation in all cases disfavours SN1 mechanism. Involvement of addition ionization mechanism along with SN2 may be another factor which ...
Chapter 13, sections 13.5 - Properties of Aldehydes and Ketones
... which contains Cu2+, reacts with aldehydes that have an adjacent OH group. • An aldehyde is oxidized to a carboxylic acid, while Cu2+ is reduced to give red Cu2O(s). ...
... which contains Cu2+, reacts with aldehydes that have an adjacent OH group. • An aldehyde is oxidized to a carboxylic acid, while Cu2+ is reduced to give red Cu2O(s). ...
Nucleophilic Substitution and b
... Here is the crux of the matter: how can the non-reacting carbon change its configuration??? Further it does not always change but only if configuration of the reacting carbon changes!! We got a mixture of enantiomers, a racemic mixture. Something strange is happening!! Expect sulfur to attack the C- ...
... Here is the crux of the matter: how can the non-reacting carbon change its configuration??? Further it does not always change but only if configuration of the reacting carbon changes!! We got a mixture of enantiomers, a racemic mixture. Something strange is happening!! Expect sulfur to attack the C- ...
Chapter 17
... a key intermediate in Fischer esterification is the tetrahedral carbonyl addition intermediate formed by addition of ROH to the C=O group O ...
... a key intermediate in Fischer esterification is the tetrahedral carbonyl addition intermediate formed by addition of ROH to the C=O group O ...
10.3 PREPARATION OF ETHERS
... ether synthesis. Because the basicity of an alkoxide ion is comparable to that of hydroxide ion, much of the discussion about the use of hydroxide as a nucleophile also applies here. Thus, alkoxide ions react by the SN2 mechanism and are subject to the usual SN2 limitations. They give good yields wi ...
... ether synthesis. Because the basicity of an alkoxide ion is comparable to that of hydroxide ion, much of the discussion about the use of hydroxide as a nucleophile also applies here. Thus, alkoxide ions react by the SN2 mechanism and are subject to the usual SN2 limitations. They give good yields wi ...
Answers - Benjamin
... d The key feature of the i.r. spectrum is the change at ca 3000 cm–1 indicating the loss of a phenolic hydroxyl and/or carboxylic acid group. The n.m.r. spectra show the loss of a carboxylic acid –OH group, and the gain of a methyl group. The CH3 group is in an environment different to that in aspir ...
... d The key feature of the i.r. spectrum is the change at ca 3000 cm–1 indicating the loss of a phenolic hydroxyl and/or carboxylic acid group. The n.m.r. spectra show the loss of a carboxylic acid –OH group, and the gain of a methyl group. The CH3 group is in an environment different to that in aspir ...
Aldehydes and Ketones - Belle Vernon Area School District
... Rxns of Aldehydes and Ketones Reduction of aldes and kets to alcohols ...
... Rxns of Aldehydes and Ketones Reduction of aldes and kets to alcohols ...
Oxidation Reactions
... 2. Chemoselectivity - oxidation of primary alcohols requires control as there are two potential products: the carboxylic acid or the aldehyde. Aldehydes are extremely important in organic synthesis; thus controlled oxidation from an alcohol to an aldehyde, avoiding over-oxidation to the carboxylic a ...
... 2. Chemoselectivity - oxidation of primary alcohols requires control as there are two potential products: the carboxylic acid or the aldehyde. Aldehydes are extremely important in organic synthesis; thus controlled oxidation from an alcohol to an aldehyde, avoiding over-oxidation to the carboxylic a ...
Wolff rearrangement
The Wolff rearrangement is a reaction in organic chemistry in which an α-diazocarbonyl compound is converted into a ketene by loss of dinitrogen with accompanying 1,2-rearrangement. The Wolff rearrangement yields a ketene as an intermediate product, which can undergo nucleophilic attack with weakly acidic nucleophiles such as water, alcohols, and amines, to generate carboxylic acid derivatives or undergo [2+2] cycloaddition reactions to form four-membered rings. The mechanism of the Wolff rearrangement has been the subject of debate since its first use. No single mechanism sufficiently describes the reaction, and there are often competing concerted and carbene-mediated pathways; for simplicity, only the textbook, concerted mechanism is shown below. The reaction was discovered by Ludwig Wolff in 1902. The Wolff rearrangement has great synthetic utility due to the accessibility of α-diazocarbonyl compounds, variety of reactions from the ketene intermediate, and stereochemical retention of the migrating group. However, the Wolff rearrangement has limitations due to the highly reactive nature of α-diazocarbonyl compounds, which can undergo a variety of competing reactions.The Wolff rearrangement can be induced via thermolysis, photolysis, or transition metal catalysis. In this last case, the reaction is sensitive to the transition metal; silver (I) oxide or other Ag(I) catalysts work well and are generally used. The Wolff rearrangement has been used in many total syntheses; the most common use is trapping the ketene intermediate with nucleophiles to form carboxylic acid derivatives. The Arndt-Eistert homologation is a specific example of this use, wherein a carboxylic acid may be elongated by a methylene unit. Another common use is in ring-contraction methods; if the α-diazo ketone is cyclic, the Wolff rearrangement results in a ring-contracted product. The Wolff rearrangement works well in generating ring-strained systems, where other reactions may fail.