<?xml version="1.0" encoding="UTF-8" standalone="yes"?><oembed><version><![CDATA[1.0]]></version><provider_name><![CDATA[amphoteros]]></provider_name><provider_url><![CDATA[http://amphoteros.com]]></provider_url><author_name><![CDATA[ayudin2013]]></author_name><author_url><![CDATA[https://amphoteros.com/author/ayudin2013/]]></author_url><title><![CDATA[Going retro]]></title><type><![CDATA[link]]></type><html><![CDATA[<p>Chemists like to coin new terms, which is particularly meaningful when there is a connection to the place of discovery of a given molecule or process. Graduate students are usually well aware of munchnones. These intriguing intermediates are named after Munich, where Professor Huisgen spent a good portion of his career and where he coined the term. Comparatively less known are sydnones, which differ from munchnones by the presence of nitrogen. As a matter of fact, sydnones predate munchnones. They were developed in Sydney by Earl and Mackney back in 1935. Below is an awesome paper by Harrity and co-workers I came across. It showcases the use of sydnones in heterocyclic synthesis. <a href="https://amphoteros.files.wordpress.com/2014/03/rrr1.jpg"><img id="i-2127" class="size-full wp-image" src="https://amphoteros.files.wordpress.com/2014/03/rrr1.jpg?w=650" alt="Image" srcset="https://amphoteros.files.wordpress.com/2014/03/rrr1.jpg?w=650 650w, https://amphoteros.files.wordpress.com/2014/03/rrr1.jpg?w=150 150w, https://amphoteros.files.wordpress.com/2014/03/rrr1.jpg?w=300 300w, https://amphoteros.files.wordpress.com/2014/03/rrr1.jpg?w=768 768w, https://amphoteros.files.wordpress.com/2014/03/rrr1.jpg 965w" sizes="(max-width: 650px) 100vw, 650px" /></a></p>
<p style="text-align:center;"><a href="http://onlinelibrary.wiley.com/doi/10.1002/anie.200703767/abstract" rel="nofollow">http://onlinelibrary.wiley.com/doi/10.1002/anie.200703767/abstract</a></p>
<p>While the paper is hardly new, I marvel at this way of introducing boron atoms into heterocycles. Cycloaddition/retro-cycloaddition does the trick here. By the way, there is a great review by Mike Willis that contains a lot of other, equally intriguing, cases that employ retro-cycloadditions. Here is a link to Mike&#8217;s review:</p>
<p style="text-align:center;"><a href="http://pubs.rsc.org/en/content/articlehtml/2013/cs/c2cs35316d" rel="nofollow">http://pubs.rsc.org/en/content/articlehtml/2013/cs/c2cs35316d</a></p>
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