Ortho Meta Para Directing Groups Ppt

All other op-directors are activating and all other deactivating groups are m-directors. 4232020 The key difference between ortho para and meta substitution is that ortho substitution has two substituents in 1 and 2 positions of the ring but para substitution has two substituents in 1 and 4 positionsMeanwhile meta substitution has two substituents in 1 and 3 positions.

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Carbons are sp2 not a second p bond Benzyne can be trapped by a Diene.

Ortho meta para directing groups ppt. Direct further substitution to positions ortho and para to themselves Alkyl group has most effect on the ortho and para positions 19 20. The three possible disubstituted products ie ortho para and meta are not formed in equal amounts. Meta directing groups are electron-withdrawing groups.

Deactivators not halogens are meta-directing. Thus the nitro group is a meta directing group. Ortho-para directors direct an incoming electrophile to positions ortho andor.

OH and NH 2 Alkoxyl and amino groups have a strong electron- donating resonance effect Most. Heres a concrete example. OrthoPara Or Meta Directing Book B 1 HB r FeBr3 cat or Fe cat r2 H r Deactivating OrthoPara 172 C Cl2 AlCl 3 cat HCl H l Deactivating OrthoPara 172 The halides are unique in being deactivating but orthopara directing.

The first exercise is to make sure you know which groups are activators and deactivators as well as how that relates to the Ortho- Para- and Meta directing. In the following practice problems we will go over the Ortho- Para- and Meta directors in Electrophilic Aromatic Substitution. The halide ions which are electron-withdrawing but ortho para directing are the exception.

Acylation then Reduction Side Chain Reactions 2 Oxidation of Alkyl Substituents 3 Benzylic Bromination with NBS 5 Reduction of Nitro Groups Directing Effects orthopara-Directing Activating Groups Nitration of Anisole Nitration Affords ortho and para. In an electrophilic aromatic substitution reaction existing substituent groups on the aromatic ring influence the overall reaction rate or have a directing effect on positional isomer of the products that are formed. 11182014 Orthopara directing groups have most negative charges on the orthopara positions while meta directing groups often possess the largest negative charge on the meta position.

Deactivators halogens are ortho-para directing. Acyl groups are resonance deactivators. Ortho and para attack produces a resonance structure which places the arenium cation next to and additional cation.

Mech 2 HNO3. Undergoes a Diels-Alder rxn Benzyne intermediate has 2 reactive sites Mixture of Regioisomers Nitration Affords ortho and para Products Activating orthopara directors Nitration of Toluene meta-Directing Deactivating Groups Electron-Withdrawing Nitro Group Directs meta. 9232020 Acyl groups are meta Directors.

An electron donating group EDG or electron releasing group ERG Z in structural formulas is an atom or functional group that donates some of its electron density into a. The directive influence of OH phenolic group. 1292018 Examples of ortho- para directors are hydroxyl groups ethers amines alkyl groups thiols and halogens.

Our results do not support that orthopara directing groups are electron donors and meta directing groups are electron acceptors. Groups that have an unshared electron pair on the atom attached to the aromatic ring such as amino hydroxyl alkoxyl and amides or esters with the oxygen or nitrogen directly. Maurice Odago Created Date.

They are also orthopara directors. Thus the nitro group is a meta directing group. Alkyl Groups Alkyl groups activate by induction.

Therefore it is an. The nature of the substituents already present on the benzene ring determines the position of the second substitution. The terms ortho para and meta refer to different structures of a benzene ring with at.

Thus the methyl group is an ortho para directing group. 192013 1o RX Typically Undergoes Shift Straight-chain Alkylation can be Accomplished in 2 steps. Combined with the orthometapara distribution to give partial rate factors for substitution at the various ring.

Ortho-para directing and meta. Ortho Para-Directing and Meta-Directing Groups. The nitration of methoxybenzene also known as anisole.

Therefore depending on the character of the initial substituent R a subsequent substituent would be placed at the ortho or para position if R is an activatorhalogen or at the meta position if it is a deactivator but not a halogen. Importance of Directing Effects in Synthesis. Most neutral species we studied here are.

In this way it has been found that every group can be put into one of the two classes. By default the meta product forms faster because it lacks this destablizing. Ortho para directing groups are electron-donating groups.

This destabilizes the arenium cation and slows down ortho and para reaction. The halide ions which are electron-withdrawing but ortho para directing are the exception. All meta directing groups All other things being equal a third group is less likely to enter between two groups for steric reasons When a meta directing group is meta to an op directing group the incoming electrophile goes predominantly ortho to the meta directing group rather than para to it there is currently no good explanation.

All alkyl groups are activating and ortho-para directing Generalization. Ortho- and para- products dominate while meta. OrthoPara Directors Alkyl substituents are electron-donating groups and they are activating groups.

8242020 Thus the methyl group is an ortho para directing group. Ortho para directing groups are electron-donating groups. 1272015 ORTHO AND PARA DIRECTING GROUP The groups which direct the incoming group to ortho and para position are called ortho and para directing groups.

The resonance structures of phenol show that the overall electron density on the benzene ring increases in comparison to benzene. Meta directing groups are electron-withdrawing groups.

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Ppt Ch 15 1 Powerpoint Presentation Free Download Id 3434389

Ppt Ch 15 1 Powerpoint Presentation Free Download Id 3434389