Scardiglia, Franco (1958) I. Reactions of non-activated aryl halides with strong basic and nucleophilic agents. II. Evidence for cyclohexene as an intermediate in the coupling reaction of phenyllithium with 1-chlorocyclohexene. III. Reactions of non-activated aryl halides with strong bases at high temperatures. IV. The synthesis of some four-membered ring compounds. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-01132006-130643
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Part I. Previous studies have shown that non-activated aryl halides are aminated by alkali amides in liquid ammonia by the way of a benzyne intermediate. Nucleophilic substitution products are formed with some strong bases and aryl halides in liquid ammonia, provided alkali amides are present. A study of the mechanism and the scope of such reactions has been made. It has been shown that the first step is the formation of benzyne through reaction of alkali amide and aryl halide. The intermediate is then attacked competitively by the various nucleophilic species (including amide ion) present in solution. Thus, when o- and p-bromotoluene were treated with sodium phenylacetylide in liquid ammonia, the product contained, in addition to aromatic amines, approximately equimolar amounts of 2- and 3-methyldiphenylacetylene and 3- and 4-methyldiphenylacetylene respectively. Benzyne has been found to be attacked by good nucleophiles. The ease of attack of nucleophilic species cannot be directly correlated either with base strength or nucleophilicity as measured in simple [...] reactions.
Part II. Cyclohexanone-2-[...] has been converted to l-phenylcyclohexene by way of 1,1-dichlorocyclohexane and 1-chlorocyclohexene. Oxidation of a benzenesulfenyl chloride derivative of 1-phenylcyclohexene gave benzoic acid which contained 23% of the radiocarbon present in 1-phenylcyclohexene. This is consistent with an elimination-addition mechanism, in which 1-chlorocyclohexene loses a molecule of hydrogen chloride to give cyclohexyne as a reaction intermediate.
Part III. The reaction of p-chloro, p-bromo and p-iodotoluene with potassium anilide in refluxing aniline gave approximately equimolar mixtures of m- and p-tolylphenylamine. These product compositions are consistent with a benzyne (elimination-addition) mechanism.
Part IV. l,l-Difiuoro-2-piperidino-3-phenyl-2-cyclobutene (I) has been obtained by treating 1,1,2-trifluoro-2-chloro-3-phenylcyclobutane with piperidine. Treatment of I with concentrated sulfuric acid gave 2-piperidino-3-phenyl-2-cyclobutenone.
|Item Type:||Thesis (Dissertation (Ph.D.))|
|Degree Grantor:||California Institute of Technology|
|Division:||Chemistry and Chemical Engineering|
|Thesis Availability:||Public (worldwide access)|
|Defense Date:||1 January 1958|
|Default Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Imported from ETD-db|
|Deposited On:||13 Jan 2006|
|Last Modified:||26 Dec 2012 02:27|
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