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Questions tagged [regioselectivity]

For questions involving selectivity as to where a functional group reacts.

14 questions with no upvoted or accepted answers
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8
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390 views

Sulfonyl azides: diazo or azide transfer?

Sulfonyl azides, $\ce{RSO2N3}$, are capable of acting as sources of electrophilic azide ("$\ce{N+3}$"), but are also capable of effecting diazo transfer, as shown in the scheme below, taken from ref 1:...
7
votes
0answers
80 views

How can organocuprates generated with catalytic Cu(I) be competitive in 1,4-addition to an enone?

Organocopper compounds (e.g. $\ce{LiCuR_2}$) are often prepared from an organolithium or Grignard reagent when a soften nucleophile is needed, such as for a conjugate addition to an $\alpha,\beta$-...
7
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0answers
647 views

Why does phenol react on oxygen in the Gattermann–Koch reaction?

When discussing the Gattermann–Koch reaction on phenol substrates, it has been said that O-acylation is a problematic competing reaction as in a phenol, there's high electron density on the O atom [...
5
votes
0answers
675 views

Why do t-butyl bromide and silver(I) nitrite form the nitroalkane, not the nitrite ester?

We know that reaction of $\ce{AgNO2}$ with alkyl halides is SN1 type reaction and follows HSAB principle. So in the reaction of $\ce{(CH3)3C Br}$ we would expect $\ce{AgBr}$ to form and also a ...
5
votes
0answers
320 views

Stability of extended enolates

I'd expect an extended enolate to be more stable than a normal enolate, when both can form, but my textbook suggests otherwise. What is the stability of an extended enolate compared with a normal ...
5
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0answers
51 views

Increasing C-alkoxycarbonylation of enolates

I am working with N-tosyl-2-piperidone and attempts to use the lithium enolate of this compound to perform an nucleophilic acyl substitution reaction on an several chloroformate esters in THF has lead ...
5
votes
0answers
158 views

Regioselectivity in Ziegler–Natta polymerisation of α-olefins

Why does the Ziegler–Natta polymerization display the regioselectivity shown in the image? Internal nucleophiles (coordinated to the metal) should attack the alkene on the less substituted end, like ...
4
votes
0answers
368 views

Regioselectivity of the Beckmann rearrangement

It seems to be that the Beckmann rearrangement is a nice way to prepare secondary amines. This can be achieved by removal of oxygen via the use of $\ce{HI}$/$\ce{P}$. However, if ketones are used, ...
3
votes
0answers
125 views

Regioselectivity in the aldolcondensation towards (Z)-Jasmon

In the synthesis of (Z)-Jasmone via aldol-condensation as shown below, how can the observed regioselectivity be explained? After all, it is also possible to form the side product shown below. I ...
2
votes
0answers
298 views

Why do the induction effects of fluorobenzene decrease electrophilic addition reactivity, conjugation effects increase selectivity?

Fluorobenzene shows signs of both the electron withdrawing and electron donating groups on benzene. Electrophilic substitution to the ring is less reactive because the fluorine is very electronegative ...
2
votes
0answers
806 views

Reactivity and selectivity in free radical halogenation of alkanes

I read about the free radical halogenation of alkanes with $\ce{X2}$ and I have the following questions: Given that the first step is the homolytic breaking of the $\ce{X-X}$ bond, and the homolytic ...
2
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0answers
470 views

Selectivity in Suzuki coupling of 2,4-dichloropyrimidine

I've seen many papers (see e.g. Synthesis 2010, 16, 2721–2724) in which the 4-chloro group of 2,4-dichloropyrimidine is selectively reacted under Suzuki coupling conditions. Is there any way where ...
1
vote
0answers
73 views

What are some possible classification tests that one can use for o-nitrobenzoic acid?

I have analyzed an IR spectrum and found out that my compound (o-nitrobenzoic acid) has a nitro group, carboxylic group, and benzene ring. I was curious to know: if regioselectivity effects the ...
0
votes
0answers
13 views

What are the unique reactions of conjugated carbon containing carbonyl compounds?

Various sources give different ideas about the reduction reaction of α,β-unsaturated carbonyl compounds which have conjugated carbon. Just like cinnamaldehyde do aliphatic α,β-unsaturated carbonyl ...