Related Concept Videos

α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction01:15

α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction

The method to achieve α-brominated carboxylic acids using a mixture of phosphorus tribromide and bromine is known as the Hell–Volhard–Zelinski reaction. The reaction is catalyzed by phosphorus tribromide, which can be used directly or produced in situ from red phosphorus and bromine. The mechanism comprises PBr3 catalyzed conversion of acid to acid bromide and hydrogen bromide. The acid bromide enolizes to its enol form in the presence of HBr. The nucleophilic enol attacks the bromine molecule...
Aldehydes and Ketones to Alkenes: Wittig Reaction Overview01:19

Aldehydes and Ketones to Alkenes: Wittig Reaction Overview

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.
Aldehydes and Ketones to Alkenes: Wittig Reaction Mechanism01:14

Aldehydes and Ketones to Alkenes: Wittig Reaction Mechanism

The Wittig reaction, which converts aldehydes or ketones to alkenes using phosphorus ylides, proceeds through a nucleophilic addition‒elimination process.
The reaction begins with the nucleophilic addition between a phosphorus ylide and the carbonyl compound. Due to its carbanionic character, phosphorus ylide acts as a strong nucleophile and attacks the electrophilic carbonyl group. This generates a charge-separated dipolar intermediate called betaine. The negatively charged oxygen atom and...
Positive Symptoms of Schizophrenia: Hallucinations and Delusions01:30

Positive Symptoms of Schizophrenia: Hallucinations and Delusions

Schizophrenia is a complex mental health disorder that can manifest with various positive symptoms, including thought, movement, and behavior disorders. These symptoms significantly disrupt cognitive and motor functions, leading to profound effects on an individual's ability to engage with the world.
Thought Disorders
Disorganized and unusual thought processes mark thought disorders in schizophrenia. One key feature is disorganized speech, where an individual's conversation includes loosely...
Hypersensitivity Reactions: Immune-Complex Reactions01:19

Hypersensitivity Reactions: Immune-Complex Reactions

Type III hypersensitivity reactions occur when antigen–antibody complexes form and activate the complement system. Normally, these complexes help the clearance of antigens by phagocytes and red blood cells. However, when large numbers of immune complexes are present, they can deposit in tissues—particularly in the walls of blood vessels—leading to inflammation and tissue injury. These deposits trigger complement activation and neutrophil recruitment, resulting in serum sickness, a systemic...
Nonenolizable Aldehydes to Acids and Alcohols: The Cannizzaro Reaction01:25

Nonenolizable Aldehydes to Acids and Alcohols: The Cannizzaro Reaction

The Cannizzaro reaction is a base-promoted redox reaction producing a primary alcohol and a carboxylic acid from two molecules of a nonenolizable aldehyde. The reaction commences when the anionic counterpart of the base attacks the carbonyl carbon, resulting in a tetrahedral alkoxide intermediate. The base then abstracts a proton from the intermediate to generate an unstable dianionic species. This intermediate enables the release of the aldehydic hydrogen as a hydride ion. An intermolecular...