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182          CHAPTER 7           
 
Useful reagents 
 
The following is a list of commonly encountered reagents for substitution and elimination reactions: 
 
Reagent Name Function 
NaCl 
Sodium 
chloride 
An ionic salt consisting of Na+ and Clˉ ions. The former (Na+) can 
be ignored in most cases, while the latter (chloride) is a strong 
nucleophile. NaCl is a source of chloride ions. 
NaBr 
Sodium 
bromide 
An ionic salt consisting of Na+ and Brˉ ions. The former (Na+) can 
be ignored in most cases, while the latter (bromide) is a strong 
nucleophile. NaBr is a source of bromide ions. 
NaI Sodium iodide 
An ionic salt consisting of Na+ and Iˉ ions. The former (Na+) can be 
ignored in most cases, while the latter (iodide) is a strong 
nucleophile. NaI is a source of iodide ions. 
NaH 
Sodium 
hydride 
Hydride is a strong base that can be used in E2 reactions. 
 
DBN A strong base that can be used in E2 reactions. 
 
DBU A strong base that can be used in E2 reactions. 
NaOH 
Sodium 
hydroxide 
Hydroxide (HOˉ) is both a strong nucleophile AND a strong base, 
and can therefore be used for either E2 or SN2 reactions, depending 
on the substrate (SN2 is favored for primary substrates, E2 is favored 
for secondary substrates, and E2 is the exclusive pathway for tertiary 
substrates). 
NaOR 
Sodium 
alkoxide 
R is an alkyl group. Examples include sodium methoxide (NaOMe) 
and sodium ethoxide (NaOEt). Alkoxide ions are both strong 
nucleophiles and strong bases. They can therefore be used for either 
E2 or SN2 reactions, depending on the substrate (SN2 is favored for 
primary substrates, E2 is favored for secondary substrates, and E2 is 
the exclusive pathway for tertiary substrates). 
t-BuOK 
Potassium tert-
butoxide 
tert-Butoxide is both a strong nucleophile and a strong base. But it is 
sterically hindered, which favors E2 over SN2 even for primary 
substrates. For E2 reactions, when more than one regiochemical 
outcome is possible, tert-butoxide will favor formation of the less 
substituted alkene. 
NaSH 
Sodium 
hydrosulfide 
HSˉ is a strong nucleophile, used in SN2 reactions. 
H2O Water 
Water is a weak nucleophile and a weak base, used in SN1 and E1 
reactions. Heat will often favor E1 over SN1. 
ROH An alcohol 
Examples include methanol (CH3OH) and ethanol (CH3CH2OH). 
Alcohols are weak nucleophiles and weak bases, used in SN1 and E1 
reactions. Heat will often favor E1 over SN1. Alcohols can also 
serve as substrates for SN1 or E1 reactions under acidic conditions. 
HX 
(X = Cl, Br, or I) 
Hydrogen 
halides 
A strong acid that serves as both a source of H+ and nucleophilic Xˉ 
where X = Cl, Br, or I. 
conc. H2SO4 
Concentrated 
sulfuric acid 
A strong acid, used to convert alcohols into alkenes. 
 
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