Cannizzaro reaction

The Cannizzaro reaction involves self oxidation-reduction between two molecules of aromatic or aliphatic aldehydes having no alpa-hydrogens...

The Cannizzaro reaction involves self oxidation-reduction between two molecules of aromatic or aliphatic aldehydes having no alpa-hydrogens when treated with a strong base. In. this reaction, one molecule of aldehyde reduces the other to a primary alcohol and is itself oxidised to, the corresponding carboxylic acid salt normally in equimolar amounts.
Cannizzaro reaction


Cannizzaro reaction of benzaldehyde formaldehyde trialkylacetaldehyde

Reaction Mechanism of Cannizzaro reaction:

The Cannizzaro reaction proceeds through hydride ion transfer mechanism ------
aldehydic hydrogen of one molecule of the aldehyde is transferred along with its bonded electron pair to the carbonyl carbon of the other one. The kinetic study of the reaction revealed that though the reaction in general follows third order kinetics (Rate [aldehyde]2[ OH]1, there are evidences of maintaining fourth order kinetics (Rate  [aldehyde] [ OH])') particularly at higher base concentrations.


Rapid addition of OH to one molecule of aldehyde results in the formation of a hydroxy alkoxide ion which like aluminium-isopropoxide acts as a hydride-ion donor to the second molecule of aldehyde.(In the final step of the reaction, the acid and the alkoxide ion exchange proton for reasons of stability.


In the presence of a very strong concentration of alkali, aldehyde first forms a doubly charged anion (I)
from which a hydride anion is transferred to the second molecule of the aldehyde to form acid and an alkoxide ion. Subsequently, the alkoxide ion acquires a proton from the solvent.






The reaction can also occur between two different aldehydes having no alpa-hydrogens when it is called crossed cannizzaro reaction.
cannizzaro reaction of benzaldehyde and formaldehyde
fig: cannizzaro reaction of benzaldehyde and formaldehyde
When formaldehyde undergoes crossed Cannizzaro reaction with other aldehydes without alpa-hydrogens, it is seen that formaldehyde is oxidized and the other is reduced. This is because the nucleophilic attack occurs more readily on formaldehyde than on other aldehydes.

COMMENTS

Name

01 Solid State,4,01 Some Basic Concepts of Chemistry,4,02 Solutions,1,02 Structure of Atom,2,03 Electrochemistry,1,03 Periodicity of Elements,1,04 Chemical Bonding,7,04 Chemical Kinetics,1,05 Gaseous State of Matter,1,05 Surface Chemistry,2,06 Chemical Thermodynamics,3,07 Equilibrium,7,07 p Block Elements,7,08 d and f Block Elements,1,08 Redox Reaction,1,09 Coordination Compounds,1,09 Hydrogen Chemistry,1,10 Haloalkanes and Haloarenes,1,10 s block Elements,1,11 Alcohols Phenols and Ethers,2,11 Some p block Elements,2,12 Aldehyde Ketones and Carboxylic Acids,4,12 Basic Organic Chemistry,1,13 Hydrocarbons Chemistry,1,13 Nitrogen Containing,3,14 Biomolecules,3,14 Environmental Chemistry,2,15 Polymer chemistry,1,16 Chemistry in Everyday life,2,20,6,2O,1,Acids Bases and Salts,1,Alcohols,1,Alcohols Phenols and Ethers Question Bank,2,Atomic Structure Question Bank,1,Basic Principles of Organic Chemistry Question Bank,1,Biomolecules Question Bank,1,Carbonyl Compounds Question Bank,2,CBSE 11,1,CBSE 12,2,CBSE Class 10 Chemistry,2,Chemical Equilibrium Question Bank,2,Chemical Kinetics Question Bank,1,Chemical Thermodynamics Question Bank,3,Chemical Weapons,1,Chemistry Book,1,Chemistry News,1,Chemistry Song,2,Chemistry Syllabus,2,Class 11,1,Class 11 Chemistry,1,Class 8 Science,1,Condensation reaction,1,COVID-19,4,Download NEET Question Papers,2,Electrochemistry,1,Electrochemistry MCQs,1,Electrochemistry MCQs with Answers,1,Exclusive Chemistry,1,Food,1,General Chemistry,5,How do I study for chemistry,2,Hydrocarbons Question Bank,1,JEE Main,2,JEE Main Chemistry,2,JEE Main Chemistry Syllabus,1,JEE Main Chemistry Syllabus 2021,1,JEE Main Hydrocarbons Previous Year Questions with Solutions,1,JEE Main Question Paper,2,Lewis dot structures,5,MCQ Practice sheet,7,MCQs with Solution,1,Name Reaction,7,NCERT CBSE Syllabus,1,NCERT Syllabus,1,NEET,8,neet sample paper by nta,1,NEET | AIPMT | JEE Main MCQs,2,NEET 2020 Question Papers,1,NEET Chemistry Syllabus,1,NEET Hydrocarbons Previous Year Questions with Solutions,1,NEET Previous Year Question Paper,4,NEET Previous Year Question Papers,1,NEET Previous Year Solved Question Papers,3,NEET Question Paper,1,NEET Question Papers 2020,1,NEET Sample Papers,1,NEET Solved Question Papers,4,Nitrogen Containing Compound Question Bank,1,Organic Name Reactions,6,Oxidation Reduction,2,p Block Elements Question Bank,4,Phenols and Ethers MCQs,1,Phenols and Ethers MCQs (NEET; JEE Main),1,Practice Paper of NEET,1,Question Papers of NEET 2020,1,Radioactivity,1,s Block Elements,1,s Block Elements MCQs,1,s Block Elements Question Bank,1,Science News,1,Solid State Chemistry Question Bank,3,SOME,1,Study Tips for Chemistry,2,Surface Chemistry Question Bank,2,WBCHSE,1,WBCHSE Model Question,1,WBJEE,1,
ltr
item
Advanced Chemistry: Cannizzaro reaction
Cannizzaro reaction
https://1.bp.blogspot.com/-0jvEN8p0HjU/X1C5JX4i-FI/AAAAAAAAApA/vlZGsXL4bEQcH-9GQBKgsrdbDTOOTcW_wCLcBGAsYHQ/w320-h213/Cannizzaro-Reaction.jpg
https://1.bp.blogspot.com/-0jvEN8p0HjU/X1C5JX4i-FI/AAAAAAAAApA/vlZGsXL4bEQcH-9GQBKgsrdbDTOOTcW_wCLcBGAsYHQ/s72-w320-c-h213/Cannizzaro-Reaction.jpg
Advanced Chemistry
https://www.advancedchemistry.in/2020/01/cannizzaro-reaction.html
https://www.advancedchemistry.in/
https://www.advancedchemistry.in/
https://www.advancedchemistry.in/2020/01/cannizzaro-reaction.html
true
4485541454572784983
UTF-8
Loaded All Posts Not found any posts VIEW ALL Readmore Reply Cancel reply Delete By Home PAGES POSTS View All RECOMMENDED FOR YOU LABEL ARCHIVE SEARCH ALL POSTS Not found any post match with your request Back Home Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sun Mon Tue Wed Thu Fri Sat January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec just now 1 minute ago $$1$$ minutes ago 1 hour ago $$1$$ hours ago Yesterday $$1$$ days ago $$1$$ weeks ago more than 5 weeks ago Followers Follow THIS PREMIUM CONTENT IS LOCKED STEP 1: Share. STEP 2: Click the link you shared to unlock Copy All Code Select All Code All codes were copied to your clipboard Can not copy the codes / texts, please press [CTRL]+[C] (or CMD+C with Mac) to copy