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Benzyl is not to be confused with phenyl with the formula C 6 H 5. The term benzylic is used to describe the position of the first carbon bonded to a benzene or other aromatic ring. For example, (C 6 H 5)(CH 3) 2 C + is referred to as a "benzylic" carbocation. The benzyl free radical has the formula C 6 H 5 CH 2 •.
The Wohl–Ziegler reaction [1] [2] is a chemical reaction that involves the allylic or benzylic bromination of hydrocarbons using an N-bromosuccinimide and a radical initiator. [3] Best yields are achieved with N-bromosuccinimide in carbon tetrachloride solvent. Several reviews have been published. [4] [5]
The reaction has been shown to work in aromatic, semi-aromatic, aliphatic, and heterocyclic substrates. The reaction works best when the ketone functional groups have no adjacent enolizable protons, as this allows aldol condensation to compete. The reaction is formally a ring contraction when used on cyclic diketones.
Heteroarenes are aromatic compounds, where at least one methine or vinylene (-C= or -CH=CH-) group is replaced by a heteroatom: oxygen, nitrogen, or sulfur. [3] Examples of non-benzene compounds with aromatic properties are furan, a heterocyclic compound with a five-membered ring that includes a single oxygen atom, and pyridine, a heterocyclic compound with a six-membered ring containing one ...
Most aliphatic compounds are flammable, allowing the use of hydrocarbons as fuel, such as methane in natural gas for stoves or heating; butane in torches and lighters; various aliphatic (as well as aromatic) hydrocarbons in liquid transportation fuels like petrol/gasoline, diesel, and jet fuel; and other uses such as ethyne (acetylene) in welding.
Under these conditions, >98% yields were observed by gas chromatography. [9] In general, the Stahl oxidation is selective for oxidizing primary alcohols over secondary alcohols (both aliphatic and benzylic), and favors the oxidation of primary benzylic alcohols over primary aliphatic alcohols when TEMPO is used as the nitroxyl radical. [1]
The term bond-dissociation energy is similar to the related notion of bond-dissociation enthalpy (or bond enthalpy), which is sometimes used interchangeably.However, some authors make the distinction that the bond-dissociation energy (D 0) refers to the enthalpy change at 0 K, while the term bond-dissociation enthalpy is used for the enthalpy change at 298 K (unambiguously denoted DH° 298).
In organic chemistry, the Hammett equation describes a linear free-energy relationship relating reaction rates and equilibrium constants for many reactions involving benzoic acid derivatives with meta- and para-substituents to each other with just two parameters: a substituent constant and a reaction constant.