Organic oxidizing reagents L2 Flashcards
What is the Swern oxidation?
Mild method to convert alcohols to aldehydes
What is the oxidant in the swern oxidation?
DMSO
What is the activator in the Swern oxidation?
Oxalyl chloride
What drives the process of the Swern oxidation?
Reduction of the sulfur atom in DMSO
What are the advantages of the Swern oxidation?
- Inexpensive reagents (DMSO)
- Avoids metal use, no toxic waste
- Easy purification (by-products are gases or water soluble)
What are the conditions required for the Swern oxidation?
Base NEt3
Temp -78c
Why are sulfur ylides stable?
They can be stabilised by resonance and therefore can be formed easily by deprotonation
What are the disadvantages of the Swern oxidation?
Me2S byproduct formed smells
Low reaction temperatures needed (-78c)
Not all alcohols/aldehydes are compatible with basic reaction conditions
What is DMP oxidation?
Very mild method for oxidising alcohols to both aldehydes and ketones
Can oxidise very sensitive alcohols due to the neutral conditions
What is the benefit of using DMP for oxidation rather than swern?
Due to the basic conditions of the swern reaction, it may cause unwanted isomerisation in sensitive substrates forming the cis isomer, which is not as stable as trans
What is a pro of DMP?
Very good reagent for oxidations
What is a con of DMP?
Due to cost and risk (both high), it is used for small-scale chemistry
What is the role of TEMPO?
Catalyses the oxidation of primary alcohols to aldehydes/acids
What are the conditions required for TEMPO oxidations?
TEMPO
NaClO
NaOCl2
NaHCO3/CH2Cl2/H2O
What are the co-oxidants for TEMPO oxidation?
NaClO Sodium hypochlorite
NaOCl2 Sodium chlorite
