Organic 6: Addition Reactions of Alkenes Flashcards
Addition
reaction in which a reagent X-Y adds to a multiple bond so that X becomes attached to one of the carbons of the multiple bond and Y to the other
Unsaturated hydrocarbons
alkenes commonly described as this because they have the capacity to react with substances that add to them
Saturated hydrocarbons
alkanes commonly described as this because they are incapable of undergoing addition reactions
Hydrogenation
addition of H2 to a multiple bond
Heat of hydrogenation
heat evolved on hydrogenation of a substance; it is the value of -delta H (degree) for the addition of H2 to a multiple bond
Heterogeneous reactions
reactions involving a substance in 1 phase with a different substance in a 2nd phase
Syn addition
describes the stereochemistry of reactions such as hydrogenation in which 2 atoms or groups add to the same face of a double bond
Anti addition
when atoms or groups add to opposite faces of the double bond
Electrophilic addition
mechanism of addition in which the species that 1st reacts with the multiple bond is an electrophile (“Electron seeker”)
Markovnikov’s Rule
when an unsymmetrically substituted alkene reacts with a hydrogen halide, the hydrogen adds to the carbon that has the greatest number of hydrogens, and the halogen adds to the carbon having fewer hydrogens
Scientific method
defines science with 4 elements - observation, law, theory, and hypothesis
Hydrolysis
a bond cleaved by reaction with water
Hydration
addition of the elements of water (H, OH) to a multiple bond
Microscopic Reversability
in any equilibrium, the sequence of intermediates and transition states encountered as reactants proceed to products in one direction, and in precisely the reverse order, in the opposite direction
Le Chatelier’s Principle
a system at equilibrium adjusts so as to minimize any stress applied to it
Spontaneous
a reaction that proceeds with a decrease in free energy (change in G is less than 0); the “official” definition: a process in which the entropy of the universe increases
Free Energy (G)
the available energy of a system
Exergonic
reactions for which the sign of delta G is negative
Endergonic
reactions for which the sign of delta G is positive
Hydroboration-oxidation
reaction sequence involving a separate hydroboration stage and oxidation stage; in the hydroboration stage, diborane adds to an alkene to give an alkylborane; in the oxidation stage, the alkylborane is oxidized with hydrogen peroxide to give an alcohol; the reaction anti-Markovnikov, syn hydration of an alkene
Retention of configuration
stereochemical pathway observed when a new bond is made that has the same spatial orientation as the bond that was broken
Vicinal
describing atoms or groups attached to adjacent atoms; in the case of a ____ dihalide, on adjacent Carbons
Bromonium ion
a halonium ion in which the halogen is bromine
Chloronium
a halonium ion in which the halogen is chlorine
Halonium ions
a species that incorporates a positively charged halogen; bridged ___ ___ are intermediates in the addition of halogens to the double bond of an alkene
Vicinal halohydrins
a compound containing a halogen and a hydroxyl group on adjacent carbons
Peroxide effect
reversal of regioselectivity observed in the addition of hydrogen bromide to alkenes brought about by the presence of peroxides in the reaction mixture
Epoxides
3-membered rings that contain oxygen
Epoxidation
conversion of an alkene to an epoxide, usually by treatment with a peroxy acid
Ozonide
a compound formed by the reaction of zone with an alkene
Ozonolysis
ozone-induced cleavage of a carbon-carbon double or triple bond
Dimer
molecule formed by the combination of 2 identical molecules
Monomer
the simplest stable molecule from which a particular polymer may be prepared
Polymer
a high-molecular weight material comprising a large number of monomer subunits
Cationic polymerization
a polymerization in which the reactive intermediates are carbocations
Polyethylene
a high-molecular weight polymer of ethylene
Free-radical polymerization
an alkene polymerization proceeding via free-radical intermediates
Coordination polymerization
a method of addition polymerization in which monomers are added to the growing chain on an active organometallic catalyst
Polypropylene
a polymer of propene
