Meet\u00ading Pro\u00adgram \u2014 Novem\u00adber 2012 Nima Nikbin Depart\u00adment of Chem\u00adi\u00adcal and Bio\u00admol\u00ade\u00adc\u00adu\u00adlar Engi\u00adneer\u00ading Uni\u00adver\u00adsi\u00adty of Delaware Newark, DE Stu\u00addent Pre\u00adsen\u00adta\u00adtion Abstract \u2014 In this paper we present the detailed mech\u00ada\u00adnism for the con\u00adver\u00adsion of DMF and eth\u00adyl\u00adene to p-xylene. The mech\u00ada\u00adnism was cal\u00adcu\u00adlat\u00aded by gas-phase DFT (Den\u00adsi\u00ad\u00adty-Func\u00ad\u00adtion\u00adal The\u00ado\u00adry) for the uncat\u00adalyzed, the Br\u00f8n\u00adst\u00aded [\u2026]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[15,13],"tags":[],"class_list":["post-3122","post","type-post","status-publish","format-standard","hentry","category-abstracts","category-meetings"],"_links":{"self":[{"href":"https:\/\/catalysisclubphilly.org\/awe9a91v\/wp-json\/wp\/v2\/posts\/3122","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/catalysisclubphilly.org\/awe9a91v\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/catalysisclubphilly.org\/awe9a91v\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/catalysisclubphilly.org\/awe9a91v\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/catalysisclubphilly.org\/awe9a91v\/wp-json\/wp\/v2\/comments?post=3122"}],"version-history":[{"count":6,"href":"https:\/\/catalysisclubphilly.org\/awe9a91v\/wp-json\/wp\/v2\/posts\/3122\/revisions"}],"predecessor-version":[{"id":3308,"href":"https:\/\/catalysisclubphilly.org\/awe9a91v\/wp-json\/wp\/v2\/posts\/3122\/revisions\/3308"}],"wp:attachment":[{"href":"https:\/\/catalysisclubphilly.org\/awe9a91v\/wp-json\/wp\/v2\/media?parent=3122"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/catalysisclubphilly.org\/awe9a91v\/wp-json\/wp\/v2\/categories?post=3122"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/catalysisclubphilly.org\/awe9a91v\/wp-json\/wp\/v2\/tags?post=3122"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nNima Nikbin<\/strong>
\nDepart\u00adment of Chem\u00adi\u00adcal and Bio\u00admol\u00ade\u00adc\u00adu\u00adlar Engi\u00adneer\u00ading
\nUni\u00adver\u00adsi\u00adty of Delaware
\nNewark, DE
\nStu\u00addent Pre\u00adsen\u00adta\u00adtion<\/em>
\n
\nAbstract<\/strong> \u2014 In this paper we present the detailed mech\u00ada\u00adnism for the con\u00adver\u00adsion of DMF and eth\u00adyl\u00adene to p-xylene. The mech\u00ada\u00adnism was cal\u00adcu\u00adlat\u00aded by gas-phase DFT (Den\u00adsi\u00adty-Func\u00adtion\u00adal The\u00ado\u00adry) for the uncat\u00adalyzed, the Br\u00f8n\u00adst\u00aded acid-cat\u00adalyzed and the Lewis acid-cat\u00adalyzed reac\u00adtion. The con\u00adver\u00adsion con\u00adsists of Diels-Alder cycload\u00addi\u00adtion and sub\u00adse\u00adquent dehy\u00addra\u00adtion of the cycloadduct, an oxa-nor\u00adbornene deriv\u00ada\u00adtive. Even though the DMF-eth\u00adyl\u00adene cycload\u00addi\u00adtion is ther\u00admal\u00adly fea\u00adsi\u00adble, we find that Lewis acids can fur\u00adther low\u00ader the acti\u00adva\u00adtion bar\u00adri\u00aders by decreas\u00ading the HOMO-LUMO gap of the addends. The cat\u00adalyt\u00adic effect may be sig\u00adnif\u00adi\u00adcant or neg\u00adli\u00adgi\u00adble depend\u00ading on whether the Diels-Alder reac\u00adtion pro\u00adceeds in the nor\u00admal or the inverse elec\u00adtron-demand direc\u00adtion. We find that Br\u00f8n\u00adst\u00aded acids are extreme\u00adly effec\u00adtive at cat\u00adalyz\u00ading the dehy\u00addra\u00adtion of the oxa-nor\u00adbornene deriv\u00ada\u00adtive, which, accord\u00ading to our cal\u00adcu\u00adla\u00adtions, can\u00adnot pro\u00adceed uncat\u00adalyzed. On the oth\u00ader hand, we find that Br\u00f8n\u00adst\u00aded acids do not cat\u00adalyze the cycload\u00addi\u00adtion. Although strong Lewis acids like Li+<\/sup> can cat\u00adalyze the dehy\u00addra\u00adtion, our cal\u00adcu\u00adla\u00adtions indi\u00adcate that rel\u00ada\u00adtive\u00adly ele\u00advat\u00aded tem\u00adper\u00ada\u00adtures would be required as they are not as effec\u00adtive as Br\u00f8n\u00adst\u00aded acids. We argue that the spe\u00adcif\u00adic syn\u00adthet\u00adic route to p-xylene is kinet\u00adi\u00adcal\u00adly lim\u00adit\u00aded by the Diels-Alder reac\u00adtion when Br\u00f8n\u00adst\u00aded acids are used and by the dehy\u00addra\u00adtion when a Lewis acid is used, with the lat\u00adter being slow\u00ader than the for\u00admer. Final\u00adly, we adduce exper\u00adi\u00admen\u00adtal data that cor\u00adrob\u00ado\u00adrate the the\u00ado\u00adret\u00adi\u00adcal pre\u00addic\u00adtions: we observe no activ\u00adi\u00adty in the absence of a cat\u00ada\u00adlyst and a high\u00ader turnover fre\u00adquen\u00adcy to p-xylene in the Br\u00f8n\u00adst\u00aded acidic zeo\u00adlite HY than in the Lewis acidic zeo\u00adlite NaY.<\/p>\n","protected":false},"excerpt":{"rendered":"