Organic Mechanism Book
Socorro Henson
The mechanism of an organic reaction is the sequence of steps in the reaction, including details of what bonds are formed and/or broken in each step. Understanding the mechanisms of organic reactions is key to understanding Organic Chemistry, and is also essential to being able to use the reactions to make useful compounds.
How To Use This Page: You will be presented with reactions in the structure drawing window below, and asked to draw the curly arrow mechanisms. Start by selecting the type of reaction you would like to work on, by clicking on one of the buttons below. Then select the level of difficulty appropriate to your prior learning and your own learning goals. Then click on the "Get Problem" button and follow the instructions that will appear in the blue rectangle underneath. Click here for help on how to draw curly arrows in the editor window. The score shown below right will give an indication of your progress. Select a different reaction type or level of difficulty when you wish to move on.
This distinguished Reaction Mechanisms Conference (RMC) has held a position of long-standing significance in mechanistic chemistry since its founding in 1946. The RMC resembles a Gordon Research Conference in both size and format. Discussion and sharing of ideas at the forefront of the field has always been the style. Subjects traditionally include organic, organometallic, inorganic, and biological studies with significant mechanistic implications. The scope has broadened in the past decade; initially the focus was on mechanistic organic chemistry in the traditional sense, with emphasis on the topics and controversies that had great impact on the development of organic chemistry as a whole. The list of the organizers for the early conferences includes the names of many of the progenitors of modern organic chemistry.
William Karney (University of San Francisco) and Kathleen Morgan (Xavier University of Louisiana) are the RMC 2024 co-chairs. Brian Gold and Jeffrey Rack, from the University of New Mexico, are the local organizers for the conference. See the 2024 Conference Website for more details
The Organic Chemistry Reaction and Mechanism Guide will help you understand more than 185 of the most common reactions encountered in undergraduate organic chemistry.
Generally I would prefer dialkyl cuprate to dialkyl cadmium for conversion of an alkyl halide to a ketone, but dialkyl cadmium will also work. Both of these reagents will convert acid halides to ketones without addition to ketones. (see JACS 1972 vol 94 8593)
One contributing factor to the high reactivity of Grignard reagents towards carbonyls is the Lewis acidic character of the magnesium, which coordinates to oxygen and activates the carbonyl carbon toward nucleophilic attack. This is much less of a problem with the less oxophilic metals copper and cadmium.
It is possible to find conditions that will selectively reduce the alkene without reducing the nitro group. It is also possible to reduce a nitro group without affecting a double bond elsewhere in the molecule.
Is the double bond conjugated to the nitro group, or is it isolated from the nitro group? Conjugation between the nitro and the double bond will make the alkene somewhat less likely to undergo catalytic hydrogenation.
Hey awesome site you have got here!!! Just a suggestion but my professor focuses in on a lot of the analytical portions of organic chemistry stuff like determining the type of carbohydrate from HIO4 (periodic acid cleavage) for carbohydrates?
Or even a section on amino acids would be awesome, like determine the sequence of amino acids in a polypeptide or the Sanger reagent/reaction! Thank you for everything!!!
I have found this site very very helpful at many points through my journey in Org 1 and 2, but now, towards the end of org 2 I am finding it less and less useful, which seems strange since there are more and more reactions. Why are there so few reactions of carboxylic acids? carboxylic acid chemistry is the core of org 2, not to mention biochemistry. It would be really really helpful if there were more of them. Also, I think there needs to be some consistency with where reactions are placed, if they are going from a type of molecule, they should all be grouped in that grouping, or maybe have two legends so reactions can be looked up based on their reactant or product.
Thanks for your thoughtful reply. I have found lots of resources for reactions of alpha-beta unsaturated ketones, but all of the reactions require basic conditions. I think the purpose for this question is to find the starting materials for the aldol reaction. I will have to read up on the reactions involving alpha-beta unsaturated ketones.
Abstract. Kinetic and mechanistic data relevant to the tropospheric degradation of aromatic volatile organic compounds (VOC) have been used to define a mechanism development protocol, which has been used to construct degradation schemes for 18 aromatic VOC as part of version 3 of the Master Chemical Mechanism (MCM v3). This is complementary to the treatment of 107 non-aromatic VOC, presented in a companion paper. The protocol is divided into a series of subsections describing initiation reactions, the degradation chemistry to first generation products via a number of competitive routes, and the further degradation of first and subsequent generation products. Emphasis is placed on describing where the treatment differs from that applied to the non-aromatic VOC. The protocol is based on work available in the open literature up to the beginning of 2001, and some other studies known by the authors which were under review at the time. Photochemical Ozone Creation Potentials (POCP) have been calculated for the 18 aromatic VOC in MCM v3 for idealised conditions appropriate to north-west Europe, using a photochemical trajectory model. The POCP values provide a measure of the relative ozone forming abilities of the VOC. These show distinct differences from POCP values calculated previously for the aromatics, using earlier versions of the MCM, and reasons for these differences are discussed.
Now I have been learning chemistry for five years. I remember when I started organic chemistry, it was fun to draw arrows between molecules to show, as if in a mathematical demonstration, how the reactions occurred. In every lesson I had, teachers explained to us how a specific reaction (for example the Shapiro reaction) occurs step by step, explaining the chemistry of each group in each intermediate as if things were obvious (you know how teachers are).
If they use some, what kind of spectrometry techniques are used to measure the amount of each intermediate? If not how do they proceed? Do they use computational chemistry? Because for example for a reaction such like a $\mathrmS_N2$ it doesn't look too tricky to find how it works, whereas for Fries rearrangement (I don't know if the mechanism is considered as accepted or not) it seems to be more tricky.
So can you explain the methods (at least the most used) to confirm a mechanism? I am aware that "confirm" does not mean that we are 100% sure, but rather that it is simply the best we have found so far.
First, please note that you cannot be sure about a mechanism. That's the real killer. You can devise experiments that are consistent with the mechanism but because you cannot devise and run all possible experiments, you can never be sure that your mechanism is correct.
It only takes one good experiment to refute a mechanism. If it's inconsistent with your proposed mechanism, and you're unable to reconcile the differences, then your mechanism is wrong (or incomplete at best).
Computational chemistry is pretty awesome now and provides some really good insights into how a specific reaction takes place. It doesn't always capture all relevant factors so you need to be careful. Like any tool, it can be used incorrectly.
You could run the reaction with reactants that have two labelled oxygens and reactants that have no labelled oxygens. Do they mix? If not, it's fully intramolecular. Otherwise, there's an intermolecular component and the mechanism as written is incomplete.
At the end, the authors were able to deduce that a number of proposed mechanisms were incorrect (they did not fit the experiment) leaving one proposed mechanism that seemed plausible. Additionally, a number of MS peaks which could well represent different intermediates were discovered in the MS analyses.
Nowadays, the popular well-known theory for kinetic chemistry called Transition State Theory has been recognized as a tool that can be used to 'judge' or 'verify' which reaction mechanism pathway will occur truly. The computational chemistry is being able to find where Transition State (TS) is, which based on theory. Existing of TS implies how difficult chemical reactions do.
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Optoelectronic devices based on hybrid halide perovskites have shown remarkable progress to high performance. However, despite their apparent success, there remain many open questions about their intrinsic properties. Single crystals are often seen as the ideal platform for understanding the limits of crystalline materials, and recent reports of rapid, high-temperature crystallization of single crystals should enable a variety of studies. Here we explore the mechanism of this crystallization and find that it is due to reversible changes in the solution where breaking up of colloids, and a change in the solvent strength, leads to supersaturation and subsequent crystallization. We use this knowledge to demonstrate a broader range of processing parameters and show that these can lead to improved crystal quality. Our findings are therefore of central importance to enable the continued advancement of perovskite optoelectronics and to the improved reproducibility through a better understanding of factors influencing and controlling crystallization.
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