![]() On or linked-to by the Website infringes your copyright, you should consider first contacting an attorney. Thus, if you are not sure content located Misrepresent that a product or activity is infringing your copyrights. Please be advised that you will be liable for damages (including costs and attorneys’ fees) if you materially Your Infringement Notice may be forwarded to the party that made the content available or to third parties such Means of the most recent email address, if any, provided by such party to Varsity Tutors. Infringement Notice, it will make a good faith attempt to contact the party that made such content available by If Varsity Tutors takes action in response to Information described below to the designated agent listed below. Or more of your copyrights, please notify us by providing a written notice (“Infringement Notice”) containing ![]() If you believe that content available by means of the Website (as defined in our Terms of Service) infringes one The compounds, in order of reactivity, are II > III > I > IV. As will be a terrible leaving group, a substitution reaction with carboxylate substrates, such as compound IV, will never occur. Methoxide is the next best leaving group, from compound III, followed by the negatively charged ethanamine leaving group from compound I. Acetate, the leaving group of compound II, is a stable ion and will readily leave in a substitution reaction. If this above explanation is confusing to you, you may also compare how good the leaving groups are. The sharing of electrons will be less favorable in the resonance form of compound III than the resonance form of compound I.įor compound IV, both resonance structures are equally stable, and the molecule will exist as an average of both structures, placing a fair amount of electron density at the carbonyl carbon, drastically reducing the electrophilicity of the central carbon. We may conclude that the resonance form of compound III contributes less to the true existence of the molecule, as oxygen is more electronegative. Now compare compounds I and III. Resonance for these molecules is essentially identical, with a nitrogen atom in compound I and an oxygen atom in compound III. ![]() This is not the case in any other pictured substrate. The resonance forms below each contribute very little to the overall molecule. Note: Remember, resonance diagrams show possible electron distributions, and a molecule exists as a weighted average of these possibilities, favoring the more stable ones.Ĭompound II is the most electrophilic substrate, as the lone pair on the central oxygen molecule must be shared between two carbonyls. This molecule will be least stable and most reactive. To determine which is the most electrophilic, we must identify the resonance diagram below that contributes the least to the overall molecule. Resonance diagrams for all four substrates show how electrons contained in the leaving group's heteroatom may be shared throughout the carbonyl system, effectively placing a partial negative charge on the electrophilic carbon. As the first step in a substitution reaction involves a nucleophilic attack at an electrophilic carbonyl carbon, we must consider the varying reactivity of the electrophilic carbonyl center. Resonance diagrams, as well as an understanding of electronegativity, will help us understand the degree to which this effect is observed in a substrate. ![]()
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