{"id":23062,"date":"2020-12-04T05:35:39","date_gmt":"2020-12-04T05:35:39","guid":{"rendered":"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=23062"},"modified":"2020-12-04T05:35:39","modified_gmt":"2020-12-04T05:35:39","slug":"is-cyanogen-chloride-fluoride-a-source-of-c%e2%a9%b8n-more-mechanistic-insights","status":"publish","type":"post","link":"https:\/\/rzepa.net\/blog\/2020\/12\/04\/is-cyanogen-chloride-fluoride-a-source-of-c%e2%a9%b8n-more-mechanistic-insights\/","title":{"rendered":"Is cyanogen chloride (fluoride) a source of  C\u2a78N(+)? More mechanistic insights."},"content":{"rendered":"<p>I asked the question in my <a href=\"https:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=23044\">previous post<\/a>. A computational mechanism revealed that AlCl<sub>3<\/sub> or its dimer Al<sub>2<\/sub>Cl<sub>6<\/sub> could catalyse a concerted 1,1-substitution reaction at the carbon of Cl-C\u2261N, with benzene displacing chloride which is in turn captured by the Al. Unfortunately the calculated barrier for this simple process was too high for a reaction apparently occuring at ~room temperatures. Comments on the post suggested using either a second AlCl<sub>3<\/sub> or a proton to activate the carbon of the C\u2261N group by coordination on to nitrogen. A second suggestion was to involve di-cationic electrophiles. Here I report the result of implementing the N-coordinated model below.<\/p>\n<figure id=\"attachment_23078\" aria-describedby=\"caption-attachment-23078\" style=\"width: 450px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-large wp-image-23078\" onclick=\"jmolApplet([450,450],'load wp-content\/uploads\/2020\/12\/CNAl.log;frame 103;spin 3;vectors on;vectors 4;vectors scale 8.0;color vectors green;vibration 6;','c1');\" src=\"https:\/\/rzepa.net\/blog\/wp-content\/uploads\/2020\/12\/CNAl-1024x889.jpg\" alt=\"\" width=\"450\" height=\"391\" \/><figcaption id=\"caption-attachment-23078\" class=\"wp-caption-text\">Click on image for \u00a03D model<\/figcaption><\/figure>\n<p>The free energy barrier \u0394G<sup>\u2021<\/sup><sub>298<\/sub> is 20.8 kcal\/mol (FAIR Data DOI: <a href=\"https:\/\/doi.org\/10.14469\/hpc\/7584\">10.14469\/hpc\/7584<\/a>), which corresponds to a facile reaction at room temperatures. There does not seem to be any need to invoke super-reactive di-cationic electrophiles in this instance.\u00a0This is yet another illustration that computational modelling nowadays is good enough to flag unviable mechanisms, and hence to instigate a search for a better model.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I asked the question in my previous post. A computational mechanism revealed that AlCl3 or its dimer Al2Cl6 could catalyse a concerted 1,1-substitution reaction at the carbon of Cl-C\u2261N, with benzene displacing chloride which is in turn captured by the Al. Unfortunately the calculated barrier for this simple process was too high for a reaction [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[],"class_list":["post-23062","post","type-post","status-publish","format-standard","hentry","category-reaction-mechanism-2"],"_links":{"self":[{"href":"https:\/\/rzepa.net\/blog\/wp-json\/wp\/v2\/posts\/23062","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rzepa.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rzepa.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rzepa.net\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rzepa.net\/blog\/wp-json\/wp\/v2\/comments?post=23062"}],"version-history":[{"count":0,"href":"https:\/\/rzepa.net\/blog\/wp-json\/wp\/v2\/posts\/23062\/revisions"}],"wp:attachment":[{"href":"https:\/\/rzepa.net\/blog\/wp-json\/wp\/v2\/media?parent=23062"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rzepa.net\/blog\/wp-json\/wp\/v2\/categories?post=23062"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rzepa.net\/blog\/wp-json\/wp\/v2\/tags?post=23062"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}