ORGANIC CHEMISTRY I
Learning outcomes of the course unit
Objectives (in agreement with the Dublin descriptors);
• Knowledge and understanding:
acquire at the basic level: a) the ability to interpret and evaluate the structure, the physical properties and the reactivity of mono-functional organic molecules and to understand their notational formalism and stereochemistry ; b) discuss the thermodynamic and kinetic aspect of organic reactions and their mechanisms.
• Applying knowledge and understanding:
through an inductive and/or deductive teaching approach, Students will be stimulated to integrate their knowledge and competences during the development of the syllabus of this course. Since the very beginning of the course efforts will be devoted to the application of a rigorous methodological approach to the comprehension of the discipline.
• Making judgments:
to accompany Students towards self-evaluation represent one of the most difficult tasks for a teacher of the first year. The more effective strategy to guide Students towards self-evaluation consists in the organization of self-evaluation tests (two during the course) and to organize two-days exercises before the written examination sessions. During these per-exam sessions Students are invited to discuss autonomously or in small groups a series of recapitulatory exercises that will then be discussed with all the class under the supervision of the teacher. In this phase, either the confrontation au pair and with the teacher will allow a candidate to evaluate his/her preparation and thus decide whether to attend the examination.
• Learning skills:
through a correct use of the scientific and technical language employed during the frontal theoretical lessons, the two hours/week of tutorial and guided exercises, tools to gradually implement the ability of Students to apprehend concepts of increasing complexity will be suggested.
• Communication skills:
regardless the individual communication ability of the single Students, an important objective of this course is to accompany all Students to acquire a rigorous disciplinary language through which, not only to learn the discipline, but also be able to transmit their knowledge and skills either to experts in the field and experts of contiguous disciplines.
Basic knowledge of concepts from General Chemistry and in particular of the electronic structures of the atoms, the chemical bonds, the acid-base and the red-ox reactions.
Course contents summary
Classification, notational aspects and physical properties of mono-functional organic compounds. Basic concepts of stereochemistry. Methodological aspects for the comprehension of substitution, addition, elimination reactions of mono-functional organic compounds
Organic compounds in the biological and in the industrial world. Carbon sources. Short review of the electronic structures of atoms, on the chemical bonds. Dipole moments, intermolecular interactions and physical properties of organic molecules. Thermodinamic and kinetic aspects of chemical reactions. Hybrid orbitals of carbon atoms.Classification, reactivity and physical properties of: alkanes, cycloalkanes, alkenes, dienes, alkynes, aromatic hydrocarbons, alkyl and aryl halides, alcohols, phenols, ethers, epoxides, thiols and sulfides, amines. Isomers, stereoisomers (conformations and configurations) chiral molecules(structure, physical properties, reactivity, reaction mechanisms and intermediates, catalysis, nomenclature, notation rules; in particular:
revision of: valence bond approach to chemical bonding, bond energy and lengths; dipoles, intermolecular interactions, thermodynamic and kinetic aspects of chemical reactions, acid-base equilibria.
Classification of functional groups. Alkanes: sp3 hybridization of carbon, methane; ethane, bond distance and angles, notational aspects. Propane and higher alkanes, IUPAC nomenclature. Conformational analysis: conformations and rotation around the C-C bond, eclipsed/staggered conformations, configurational isomers, molecular connectivity. Cycloalkanes: relative stability, conformational isomers, configurational cis-trans isomers in substituted cycloalkanes. Substitution (alogenation) reactions: experimental evidences, thermodynamic and kinetic aspects, reaction mechanism, radical intermediates, relative stability of radicals, Hammond postulate, regioselectivity.
Stereochemistry: optical activity and chirality, R,S notation, notational aspects of a stereogenic center, Newman and Fischer projections , saw-horse inerconversion. Molecules with more than one asymmetric center, enantiomers, diastereoisomers.
Alkenes: sp2 hybrid orbitals, ethylene and higher alkenes, nomenclature , cis-trans (Z-E) isomerism. Hydrogenation and relative stability of alkenes. Reactivity of alkenes: addition reactions (hydrogenation, HX, water), thermodynamic and kinetic aspects, reaction mechanism; regioselectivity, stability of carbocations, rate determining step, Markovnikov rule. Traspositions. Addition of halides, halides/water, halides/alcohols. Antimarkovnikov addition of water via BH3. Allylic species, radical addition/substituition to C=C bond anti-markovnikov rule. Carbene addition to C=C bond (Simmons-Smith). Oxydation of alkenes: synthesis of epoxides, cis-diols and trans-diols.
Alkynes: sp hybrid orbitals, acetylene: bond length/energy. Nomenclature of alkynes acidity of terminal alkynes. Addition reactions: two consecutive reactions that can be controlled: hdrogenations, Br2, HX. Addition of water and tautomerism.
Dienes: conjugated and non, hydrogenation enthalpy and relative stability, Kinetic/thermodynamic control of the HX addition reaction, reaction mechanism.
Benzene: structure, hydrogenation enthalpy, resonance energy. Aromaticity and Huckel rule. Reactivity of benzene: substitution vs. addition. Electrophilic aromatic substitution: general reaction mechanism. Wheland intermediate, resonance, Hammond postulate. Nitration, halogenation, sulfonation, alkylation. Electonic effects of substituents: Inductive and mesomeric effects of electron-attracting/donating substituents. Regiochemistry of elect. arom. subst. on monosubstituted benzenes. Short account on polycyclic aromatic compounds: naphthalene, anthracene.
Alkyl halides: structure/physical properties. Substitution reaction mechanisms SN1/SN2. Examples of SN2 reactions, experimental data on SN2 reactions, living groups, nucleophiles, role of the solvent. SN1 reactions: experimental data, reaction mechanism, role of the solvent. Protic and aportic solvents and their interactions with ion-pairs and on the nuceophilicity of the nucleophile. Elimination reactions: E2 reactions, experimental data, reaction mechanism, regiochemistry (Seytzeff/Hofmann), competition SN2/E2 ad discussion of experimental data. E1 reactions mechanism, competition E2/E1 and E1/SN1. Discussion with examples. Aromatic nucleophilic substitution: general mechanism. Substitution via elimination-addition reactions.
Alcohols: nomenclature, physical properties. Acidity and role of substituents on acidity. Alkoxdes as nucleophiles. Reactions with acids, mechanisms, synthetic scopes and limitations. Short account on phenols. Ethers: nomenclature, physical properties, synthesis (Williamson). Epoxides: reactivity with acids and bases, regio- and stereochemistry and related reaction mechanisms.
Amines: classification, nomenclature, basicity. Synthesis of amines (Gabriel). Uses of amines as nucleophyles. Hoffman elimination of quaternary ammonium salts.
. J. McMurry - Organic Chemistry - Piccin, Padova
. Brown & Foote - Organic Chemistry - EdiSES, Napoli
. Paula Yurkanis Bruice - Organic Chemistry - EdiSES,Napoli
On the Web site of the course are present copies of the trasparencies employed during the lectures and several problems sets, some of these with the methodological approach of solving.
Classroom Lectures will be supplemented with discussions and problem solving. Tutoring is provided both during the lectures months and as preparation of the final evaluation.
The final evaluation is based on one written and one oral examination based on the solution and the discussion of specific problems.
Assessment methods and criteria
Evaluation methods (written and its subsequent oral discussion):
The ability of the candidate to employ a rigorous methodological approach to the reading of the chemical and structural information of the different class of monofunctional organic compounds and its transfer to the management of their reactivity will be evaluated. The evaluation consists of two phases: written and oral discussion.
In particular the following criteria for the ponderal determination of the final score are:
• Knowledge and ability to comprehend the language and methods of organic chemistry 6/30
• Ability to apply with maestry the acquired competences 15/30
• autonomy to tackle problems related to organic chemistry 5/30
• communication ability through a rigorous chemical language 4/30
Support (additional) activities:
• The frontal lessons are integrated with tutorial activities (2 h/week).
• Two full days of guided exercises are organized before written examinations
• Teachers are willing (on appointment) every working day
• All material presented during the course are freely available online (even if chalk and blackboard will be extensively used)