{"product_id":"13-dipolar-cycloadditions-of-fluorinated-allenes-and-studies-of-fluorinated-trimethylenemethanes-9780530006789","title":"13-Dipolar Cycloadditions of Fluorinated Allenes and Studies of Fluorinated Trimethylenemethanes","description":"\u003cp\u003e • Author(s): Conrad Burkholder\u003cbr\u003e • Publisher: Dissertation Discovery Company\u003cbr\u003e • Publisher Imprint: Dissertation Discovery Company\u003cbr\u003e • BISAC: Chemistry - General\u003c\/p\u003e\u003cp\u003eAbstract: \u003c\/p\u003e\u003cp\u003e\u003c\/p\u003eThe 1,3-dipolar cycloadditions of 1,1-difluoroallene 1_, fluoroallene 2, and 1,1-difluoro-3-methyl- 1,2-butadiene 3 are reported. Dipoles studied are diazomethane 4, 2-diazopropane 5, diazofluorene 6, diphenyldiazomethane 7, diphenylnitrone 8, C-phenyl- N-methylnitrone 9, triphenylnitrone 10, mesitylnitrile oxide 1_1_, and tetracyanocarbonyl ylide 12 . \u003cp\u003e\u003c\/p\u003eReaction of 1_ with 4 is regiospecific giving 4-(difluoromethylene)-1-pyrazoline. Similar regioselectivity is observed for dipoles 5 through 12_ except for 6 and 7, which give mainly 5-(difluoromethylene)-1- pyrazolines. Regiochemistry is controlled by both electronic and steric interactions. Reaction of 2 with 4 gives only 4-(fluoromethylene)- 1-pyrazoline. Reaction of 2 with 8 gives an 86 to 14 ratio of (E)-and (Z)-4-(fluoromethylene)isoxazolidines. \u003cp\u003e\u003c\/p\u003eReactions of 3 with 4, 8, and 9 are regiospecific for the 4- (difluoromethylene )-cycloadducts. \u003cp\u003e\u003c\/p\u003eThe deazetations of the fluorinated 4-methylene- 1 -pyrazolones by photolysis and thermolysis are studied in the gas phase and in solution. The kinetic product ratios of fluorinated methylenecyclopropanes are consistent with trimethylenemethane biradical intermediates. \u003cp\u003e\u003c\/p\u003eThermodynamic parameters are determined for the gas-phase equilibria of the products. \u003cp\u003e\u003c\/p\u003eThe (difluoromethylene) cyclopropane from 6 gives cycloadducts with oxygen at room temperature and acrylonitrile at 70 . The distribution of products is consistent with formation of a highly stabilized trimethylenemethane biradical which is trapped. \u003cp\u003e\u003c\/p\u003eRegiochemistry is also studied for reactions of 1 with acrylonitrile 1_3 methacrylonitrile 1_4, 1,1-dichloro- 2,2-difluoroethylene 1_5 1 t 2- bis-( me\"tnylene)cyclobutane 16, 2,3-dicyanobutadiene 1_7 and diphenylisobenzofuran. Olefins 13, 14 . and 1J5 give 1,2-cycloadducts with fluorines mainly on the ring, a result consistent with a biradical mechanism. \u003cp\u003e\u003c\/p\u003eDienes  6_ and 1_7 give competing biradical and concerted reactions. Pluoroallene reacts non-regiospecifically with 15 . Allene 3_ with cyclopentadiene gives the Diels-Alder cycloadduct with an exocyclic difluoromethylene group. \u003cp\u003e\u003c\/p\u003eDissertation Discovery Company and University of Florida are dedicated to making scholarly works more discoverable and accessible throughout the world. This dissertation, \"13-Dipolar Cycloadditions of Fluorinated Allenes and Studies of Fluorinated Trimethylenemethanes\" by Conrad Rufus Burkholder, was obtained from University of Florida and is being sold with permission from the author. A digital copy of this work may also be found in the university's institutional repository, IR@UF. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation.","brand":"Dissertation Discovery Company","offers":[{"title":"Paperback","offer_id":47780238852247,"sku":"9780530006789","price":5963.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/3471\/1191\/files\/9780530006789.webp?v=1778043577","url":"https:\/\/atlanticbooks.com\/products\/13-dipolar-cycloadditions-of-fluorinated-allenes-and-studies-of-fluorinated-trimethylenemethanes-9780530006789","provider":"Atlantic Books","version":"1.0","type":"link"}