Nucleophiles<\/strong><\/li><\/ul>\n\n\n\nElectrophiles<\/h3>\n\n\n\n Electrophiles are electron-deficient organic reagents. It can be generalized that all the positive charge containing species<\/strong> are electrophiles. For example, H+<\/sup>, NO2<\/sub>+<\/sup>, CH3<\/sub>+<\/sup>, Cl+ <\/sup><\/p>\n\n\n\n<\/p>\n\n\n\n
Neutral molecules that are\u00a0electron deficient<\/strong>\u00a0can also act as electrophiles.\u00a0Lewis acids\u00a0like AlCl3<\/sub>\u00a0and BF3<\/sub>\u00a0are examples of\u00a0neutral electrophiles<\/strong>.<\/p>\n\n\n\nNucleophiles<\/h3>\n\n\n\n Nucleophiles are electron-rich organic reagents<\/strong>. They seek bonding centers with other nuclei and hence the name, nucleophile. It can be generalized that negative charge containing species are nucleophiles. For example, H\u2013<\/sup>, CH3<\/sub>\u2013<\/sup>, and Cl\u2013<\/sup>.<\/p>\n\n\n\nNeutral molecules with a\u00a0lone-pair of electrons<\/strong>\u00a0on the\u00a0heteroatom<\/strong>\u00a0can act as a\u00a0nucleophile. For example, H2<\/sub>O, NH3<\/sub>, CH3<\/sub>OH.Types of Reactions in Organic Chemistry<\/h2>\n\n\n\n Organic reactions are reactions that occur between organic compounds. The reactions in organic chemistry are broadly classified into six categories. Let us study in detail these different types of reactions and their products.<\/p>\n\n\n\n
Substitution Reactions<\/h3>\n\n\n\n R-X + Y \u2192 R-Y +X<\/strong><\/p>\n\n\n\nWhere R-X is the substrate, Y is the reagent (which can be electrophilic or nucleophilic) and X is called the leaving group. The term substitution<\/strong> means one group is replacing the other group<\/strong>.<\/p>\n\n\n\nTypes of Substitution Reaction:<\/strong><\/p>\n\n\n\nNucleophilic Substitution ( SN<\/sub>1, SN<\/sub>2, SN<\/sub>i)<\/li>Electrophilic Substitution (SE<\/sub>)<\/li>Nucleophilic Aromatic Substitution (SN<\/sub>Ar)<\/li>Addition Reactions<\/li><\/ol>\n\n\n\nAddition reactions\u00a0can be further classified into:<\/p>\n\n\n\n
Electrophilic Addition<\/li> Nucleophilic Addition<\/li> Elimination reactions<\/li><\/ol>\n\n\n\nElimination Reactions<\/h3>\n\n\n\n These reactions can be said to be the reverse of an addition reaction, wherein a simple molecule (HX, H2<\/sub>O) is removed from the substrate i.e. a molecule is said to be eliminated from the substrate.\u00a0Elimination reaction\u00a0can be classified further into E1, E2, E1CB<\/p>\n\n\n\nOxidation and reduction reactions<\/li> Pericyclic reactions<\/li> Molecular rearrangements<\/li><\/ol>\n\n\n\nField Effect in Organic Chemistry<\/h2>\n\n\n\nInductive Effect<\/h3>\n\n\n\n It is an electron delocalization effect<\/strong> via \u03c3 bonds that arises due to the difference in electronegativities. For example, in a \u03c3 bonded organic compound like C-C-C-Cl, the carbon attached to the chlorine atom can be referred to as the \u03b1-carbon, and the one adjacent that carbon as the \u00df-carbon and so on.<\/p>\n\n\n\nNow, since\u00a0Chlorine is more electronegative than carbon<\/strong>, it withdraws the electrons that are present via the \u03c3 bond toward itself, thereby making C\u03b1 fractionally positive. Since it is devoid of electrons, C\u03b1 now being slightly electropositive than C\u00df pulls the\u00a0sigma bonded electrons\u00a0of C\u03b1-C\u00df bond toward itself and in this process, it makes C\u00df slightly electropositive.<\/p>\n\n\n\nThe electron-withdrawing effect of the Chlorine atom is being transmitted through the carbon chain via the \u03c3 bonds<\/strong>. This transmission of charges decreases rapidly with the number of intervening \u03c3 bonds. We can practically ignore this effect beyond C\u00df.<\/p>\n\n\n\nThe arrow is pointed toward the\u00a0more electronegative atom. If a group withdraws the electron from carbon, it makes carbon slightly electropositive.\u00a0Such groups are called -I groups<\/strong>\u00a0and the effect as -I effect<\/strong>. For example, -Cl, -Br, -CN and -NO2<\/sub>\u00a0are -I groups.<\/p>\n\n\n\nGroups that release electrons towards carbon are termed as\u00a0+I groups<\/strong>\u00a0and the effect is termed as +I\u00a0inductive effect in organic chemistry. For example, alkyl groups like -CH3 are\u00a0+I groups<\/strong>.<\/p>\n\n\n\nElectromeric Effect<\/h3>\n\n\n\n It is the temporary delocalization of \u03c0-electrons in a compound containing multiple covalent bonds. It is important to note that it is only a temporary effect, that is, it occurs only when a reagent is added.\u00a0Electromeric Effect\u00a0in organic chemistry can be classified into two types:<\/p>\n\n\n\n
Positive Electromeric Effect<\/strong><\/li>Negative Electromeric Effect<\/strong><\/li><\/ul>\n\n\n\nPositive Electromeric Effect<\/h4>\n\n\n\n When the \u03c0-electrons<\/strong> are given to the attacking reagent<\/strong>. For example, the reactions alkenes and alkynes mostly occur via +E, this reaction is also called electrophilic addition.Positive Electromeric Effect<\/strong><\/p>\n\n\n\nThe proton adds at C-1 as the \u03c0-electrons were given to the attacking reagent (H+<\/sup>). This results in the formation of a carbocation.<\/p>\n\n\n\nNegative Electromeric Effect<\/h4>\n\n\n\n When the \u03c0-electrons<\/strong> are shifted to a more electronegative atom (O, N, S) joined via multiple bonds<\/strong>. For example, the reactions of aldehydes and ketones occur predominantly by -E effect. It is also called nucleophilic addition.Negative Electromeric Effect<\/strong><\/p>\n\n\n\nThe CN- ion adds to the C atom of the carboxy group opposite to the movement of the \u03c0-electron cloud.<\/p>\n\n\n\n
Mesomeric Effect<\/h3>\n\n\n\n Molecules possessing sigma-bonds and\u00a0pi-bonds\u00a0alternatively exhibit the mesomeric effect. The effect is exhibited due to the permanent delocalization of \u03c0-bonds. This\u00a0increases the number of resonating structures<\/strong>\u00a0which makes the molecules of organic chemistry\u00a0more stable<\/strong>. Such kind of a system where there are alternative sigma and pie bonds are called\u00a0conjugated<\/strong>.<\/p>\n\n\n\nTypes of Mesomeric Effect<\/strong><\/p>\n\n\n\nPositive mesomeric effect<\/li> Negative mesomeric effect:<\/li><\/ul>\n\n\n\nPositive Mesomeric Effect<\/h4>\n\n\n\n This effect is exhibited when the direction of the delocalization of electrons is away from the position<\/strong> where the group is attached. Normally groups having a lone pair of electrons attached to a conjugated system push electrons into the conjugated system, that is, away from them.<\/p>\n\n\n\nGroups in organic chemistry showing positive mesomeric effect (+M) effect are -OH, -OR, -NH2<\/sub>, -SH, -X, etc.<\/p>\n\n\n\nNegative Mesomeric Effect<\/h4>\n\n\n\n This effect is exhibited when the direction of the delocalization of electrons is towards the position<\/strong> where the group is attached. These are generally electron-withdrawing groups of organic chemistry.<\/a><\/p>\n\n\n\nResonance Effect<\/h2>\n\n\n\n For certain molecules like carbonate ion (CO3<\/sub>2-<\/sup>), one single Lewis structure would not be enough to explain all of the properties. In that case, the molecule is said to have more than one structure.<\/p>\n\n\n\nEach of those structures can explain\u00a0some of the properties but not all of the properties<\/strong>. The actual structure of the molecule is a hybrid of all the possible structures (canonical forms). This phenomenon is called\u00a0resonance\u00a0in organic chemistry. If resonance occurs, each bond would be both,\u00a0a\u00a0single bond and a double bond<\/strong>\u00a0at the same time i.e. the bond order would lie between one and two.<\/p>\n\n\n\nResonating structures should fulfil the following criteria:<\/strong><\/p>\n\n\n\nAll atoms should have the same positions in all the structures.<\/li> There should have the same number of paired and unpaired electrons.<\/li> The structures should have almost the same energies.<\/li><\/ol>\n\n\n\nNote:<\/strong> Canonical forms do not have any existence in reality.<\/p>\n\n\n\nResonance Energy<\/h3>\n\n\n\n The energy difference between the most stable canonical form and the resonance hybrid is known as Resonance Energy.<\/strong> The more the resonance energy, the more is the stability.<\/p>\n\n\n\nRules for finding out the most stable canonical form:<\/strong><\/p>\n\n\n\nThe canonical form with no charges is the most stable<\/li> The canonical form with more number of covalent bonds is more stable<\/li> The canonical form where unlike charges are in close proximity are more stable<\/li> If there are to be charged, the negative charge should be on an electronegative atom. Then this canonical form is said to be more stable.<\/li><\/ol>\n\n\n\nRole of Steric Hindrance<\/h2>\n\n\n\n The structure and reactivity of many compounds in organic chemistry are greatly dictated by the presence of bulky groups or constituents in the molecule. This is called steric hindrance<\/strong>. It arises because of inter-electronic repulsions<\/strong> due to spatial crowding amongst bulky groups. Using steric factors, we can conclude that trans-2-butene is more stable than cis-2-butene.Steric Hindrance in Organic Chemistry<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"What are Carbanions? They are generated by heterolytically cleaving a group attached to carbon without removing the bonded electrons. This makes the carbon have a pair of electrons, thereby, imparting a negative charge on the carbon. CH3\u2013 is isoelectronic with NH3 and it is sp3 hybridized and the shape is pyramidal owing to the presence of a lone pair of electrons. Formation of […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[299],"tags":[],"_links":{"self":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/2761"}],"collection":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/comments?post=2761"}],"version-history":[{"count":0,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/2761\/revisions"}],"wp:attachment":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/media?parent=2761"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/categories?post=2761"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/tags?post=2761"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"Carbanions](\"https:\/\/cdn1.byjus.com\/wp-content\/uploads\/2019\/03\/word-image322-e1552291545555.png\")
<\/p>\n\n\n\n![\"Intermediates](\"https:\/\/cdn1.byjus.com\/wp-content\/uploads\/2019\/03\/word-image328-e1552291502863.png\" "\\"Intermediates")
<\/figure>\n\n\n\n![\"Transition](\"https:\/\/cdn1.byjus.com\/wp-content\/uploads\/2019\/03\/word-image331-e1552291468453.png\" "\\"Transition")
<\/figure>\n\n\n\n![\"Inductive](\"https:\/\/cdn1.byjus.com\/wp-content\/uploads\/2019\/03\/word-image334-e1552291453788.png\" "\\"Inductive")
<\/figure>\n\n\n\n![\"Inductive](\"https:\/\/cdn1.byjus.com\/wp-content\/uploads\/2019\/03\/word-image336-e1552291439244.png\" "\\"Inductive")
<\/figure>\n\n\n\n![\"Electromeric](\"https:\/\/cdn1.byjus.com\/wp-content\/uploads\/2019\/03\/word-image338-e1552291418860.png\")
<\/p>\n\n\n\n![\"Electromeric](\"https:\/\/cdn1.byjus.com\/wp-content\/uploads\/2019\/03\/word-image339-e1552291400990.png\")
<\/p>\n\n\n\n![\"](\"https:\/\/cdn1.byjus.com\/wp-content\/uploads\/2019\/03\/word-image344-e1552291003512.png\")
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