mechanisms

Our New Book, “Practice Organic Mechanisms”, Is Out

Our New Book, “Practice Organic Mechanisms”, Is OutMarch 14, 2016

Today I’m delighted to announce a new book – Practice Organic Mechanisms, co-written with Dr. Michelle Sulikowski, Senior Lecturer of Organic Chemistry at Vanderbilt University. Practice Organic Mechanis…

Tagged as: mechanisms, practice organic mechanisms

Alkyne Addition Reactions – The “Concerted” Pathway

Alkyne Addition Reactions – The “Concerted” PathwayJune 4, 2013

How does the chemistry of alkynes compare to alkenes? As we’ve seen in some previous posts, there are some significant differences, but a lot of the chemistry “rhymes”, if you will. In the series on …

Tagged as: alkenes, alkynes, anti, hydroboration, lindlar, mCPBA, mechanisms, oso4, sodium, syn

Alkyne Addition Reactions: The 3-Membered Ring Pathway

Alkyne Addition Reactions: The 3-Membered Ring PathwayMay 29, 2013

Last time we discussed the similarities (and differences) between the carbocation pathway for alkenes and alkynes. In this post, we’ll do the same for the “3-membered ring pathway”. If you’ll r…

Tagged as: alkynes, antiaromatic, bromine, chlorination, chlorine, halogenation, mechanisms, trans

Bromination of Alkenes: The Mechanism

Bromination of Alkenes: The MechanismMarch 15, 2013

In the last post of this series we showed how the mechanism for bromination of alkenes can’t possibly go through a carbocation intermediate. Why not? We have at least 3 good reasons: The two atoms that form new …

Tagged as: alkenes, anti, bromination, bromonium, chlorination, halogenation, halonium, markovnikov, mechanisms, syn

Reaction Friday: Friedel Crafts Acylation

Reaction Friday: Friedel Crafts AcylationMarch 2, 2012

Today’s Reaction Friday is about the Friedel Crafts acylation of benzene and other aromatics, an important example of electrophilic aromatic substitution. One thing I forgot to say at the bottom is that there…

Tagged as: acid halides, acyl halides, AlCl3, aromaticity, aromatics, benzene, electrophiles, electrophilic aromatic substitution, FeCl3, Friedel-Crafts, mechanisms, Reaction Friday

Curved Arrows (2): Initial Tails and Final Heads

Curved Arrows (2): Initial Tails and Final HeadsFebruary 29, 2012

Here’s a handy little trick for accounting for charges when you draw curved arrows. You know by now that curved arrows are our accounting system for showing how electrons move, from the tail (electron donor, sou…

Tagged as: curved arrows, drawing, electron accounting, formal charge, how electrons move, mechanisms, Reaction Mechanisms

The Third Most Important Question to Ask When Learning A New Reaction

The Third Most Important Question to Ask When Learning A New ReactionFebruary 20, 2012

When learning any new reaction, I think you always have to start with the “what”. What bonds are forming, and what bonds are breaking. After you answer “what”, then you can start asking “…

Tagged as: curved arrows, formal charge, lone pairs, mechanisms, pi bonds, sigma bonds

Reaction Friday: Addition of Grignard Reagents to Ketones

Reaction Friday: Addition of Grignard Reagents to KetonesFebruary 18, 2012

Grignard reagents are very useful carbon-based nucleophiles and will readily form carbon-carbon bonds with carbonyl compounds. Here the reaction of Grignard reagents with ketones is described, along with several examp…

Tagged as: alcohols, grignard reagents, ketones, mechanisms, nucleophiles, organometallics, Reaction Friday

Summary Sheet #7 – 21 Carbonyl Mechanisms on 1 page

Summary Sheet #7 – 21 Carbonyl Mechanisms on 1 pageApril 20, 2011

If you feel sometimes like mechanisms in carbonyl chemistry keep repeating themselves, you aren’t just imagining things. The fact is that there IS  a lot of repetition. This has been covered before – the …

Tagged as: aldol, carboxylic acids, cheat sheets, claisen, esters, fischer, mechanisms, Summary Sheets

Carbonyl Chemistry: Learn Six Mechanisms For the Price Of One

Carbonyl Chemistry: Learn Six Mechanisms For the Price Of OneMarch 28, 2011

So at some point during Org 2, you will probably be expected to learn a whole slew  of mechanisms. Like these: Conversion of carboxylic acids to esters (Fischer esterification) Hydrolysis of esters to carboxylic acid…

Tagged as: carbonyls, mechanisms, org 2, paped, shortcuts, summaries