Predict the major product(s) you would obtain from sulfonation of the following compounds: (a) F

step 1 All right. We're going to be sulfinating some compounds here. We don't have to worry about any i

Predict the major product(s) you would obtain from...

Key Concepts

Electrophilic Aromatic Substitution (EAS)

This is a fundamental reaction mechanism in which an electrophile selectively substitutes a hydrogen atom on an aromatic ring. The mechanism typically involves the formation of a resonance-stabilized carbocation intermediate (known as the sigma complex) and is highly influenced by the nature of the substituents already present on the benzene ring.

Sulfonation Reaction Mechanism

Sulfonation is a type of EAS where the electrophile is sulfur trioxide (SO3) or protonated forms derived from concentrated sulfuric acid. In this reaction, the aromatic ring attacks the electrophilic sulfur atom, leading to the introduction of a sulfonic acid group (-SO3H) onto the ring.

Activating vs. Deactivating Groups

Substituents on an aromatic ring can influence its reactivity by either donating or withdrawing electron density. Activating groups increase the rate of EAS by donating electron density (often through resonance), while deactivating groups decrease the rate of reaction by withdrawing electron density. The nature of the substituent determines not only the reactivity of the ring but also the orientation of the incoming substituent.

Directing Effects

Substituents on the aromatic ring also dictate the preferred position of incoming electrophiles by either stabilizing or destabilizing the intermediate sigma complex at certain positions. Activating groups typically direct electrophiles to the ortho and para positions, whereas strong deactivating groups tend to direct substitution to the meta position.

Resonance Effects in Substituted Aromatic Rings

Resonance effects describe how substituents with lone pairs or pi-electrons can interact with the conjugated system of the aromatic ring. These effects play a key role in the stabilization of intermediates during EAS, thereby influencing both the regioselectivity and the overall reactivity of the aromatic compound.

Transcript

00:01 All right.

00:01 We're going to be sulfinating some compounds here.

00:05 We don't have to worry about any incompatible substrates with sulfination.

00:09 So we're going to go strictly by the directing group here.

00:13 We'll start with a.

00:15 Right.

00:15 So fluorine is a orthoparadirector, right? so you're going to be in a mixture of ortho -paraproducts.

00:27 So probably going to favor the para position just because the sulfonic acid, group is pretty bulky, even though fluorine is pretty small, but you might still get some strain there.

00:44 So you'll get the orthoparoproducts there.

00:46 In terms of b, right, you have a, you have this methoxy, i keep calling it a methoxy group, i'm sorry, you have this phenol, this oh that's going to want to ortho -paradirect.

00:58 Coincidentally, the bromine is going to want to also ortho -paradirect.

01:02 So you pretty much have agreement between the two substituents that are going to want to put that thing in all three positions.

01:11 It's probably less so going to want to go here because it's between both of those substituents that are kind of big.

01:18 Bromene's pretty big.

01:19 The oh bond is swinging around in all directions.

01:24 But all three products are definitely possible just based off of the directing abilities.

01:39 So you'll get this guy here.

01:43 I'm going to move d over.

01:48 I might put c and d on my next page.

01:50 We'll see.

01:57 Right.

01:57 So we'll put him over here.