Reactivity in Chemistry

Carbonyl Addition

CO25.  Summary of Elementary Steps

  The reactions of carbonyls can become very complicated, involving many steps.  In essence, though, the steps involve only a few, different elementary reactions.

In many of the reactions of anionic and semi-anionic nucleophiles, these two steps complete the entire reaction mechanism.  However, if an additional lone pair can be revealed at the nucleophilic atom (often by transferring a proron away from this site), additional steps occur.

Many mechanisms involve a number of proton transfers and pi donations.  These steps occur over and over, inching the molecule along step by step towards the product.  Usually, each proton transfer helps to prepare an atom for eventual removal via pi donation.

Occasionally, if the nucleophile is neutral, these steps are preceded by an initial activation step.



This site is written and maintained by Chris P. Schaller, Ph.D., College of Saint Benedict / Saint John's University (with contributions from other authors as noted).  It is freely available for educational use.

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Structure & Reactivity in Organic, Biological and Inorganic Chemistry by Chris Schaller is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License

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