Ppm level palladium catalyzed regioselective remote arylation of alkenyl alcohols

  • 0Department of Chemistry and Biochemistry, Texas Tech University Lubbock Texas 79409 USA Haibo.Ge@ttu.edu.

|

Summary

This summary is machine-generated.

Related Concept Videos

Radical Anti-Markovnikov Addition to Alkenes: Overview 01:25

3.3K

The addition of hydrogen bromide to alkenes in the presence of hydroperoxides or peroxides proceeds via an anti-Markovnikov pathway and yields alkyl bromides.

The observed regioselectivity can be explained based on the radical stability and steric effect. From the radical stability perspective, adding hydrogen bromide in the presence of peroxide directs the bromine radical at the less substituted carbon via a more stable tertiary radical intermediate. Similarly, in the steric framework, the...

Regioselectivity of Electrophilic Additions-Peroxide Effect 02:35

8.5K

In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.

In the first...

Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation 02:47

17.9K

Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.

Mechanism
The hydroboration-oxidation reaction is a two-step...

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule 02:17

14.0K

If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...

Aldehydes and Ketones to Alkenes: Wittig Reaction Overview 01:19

7.6K

The Wittig reaction is the conversion of carbonyl compounds-aldehydes and ketones-to alkenes using phosphorus ylides, or the Wittig reagent. The reaction was pioneered by Prof. Georg Wittig, for which he was awarded the Nobel Prize in Chemistry.

Phosphorus ylide is a neutral molecule containing a negatively charged carbon directly bonded to a positively charged phosphorus atom. The molecule is stabilized by resonance.

The Wittig reagents are synthesized from unhindered alkyl halides in two...

Preparation of Alkynes: Alkylation Reaction 02:27

10.0K

Introduction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.

The reaction takes place in two steps:
1. The first step is the deprotonation of the terminal alkyne by the strong base forming an acetylide ion.

2. The second step is a nucleophilic...