Which of the leaving groups attached to the "R" has a higher nucleophilicity: #"R-OH"_2^+#, #"R-OEt"#, #"R-Br"# ?
1 Answer
Jan 6, 2015
EtO⁻ has the highest nucleophilicity.
The leaving groups are H₂O, EtO⁻, and Br⁻.
The best nucleophiles have a negative charge, so that rules out H₂O as a candidate.
Br⁻ is the conjugate base of the strong acid, HBr. So Br⁻ is a weak base and a poor nucleophile.
EtO⁻ is the conjugate base of the weak acid EtOH. So EtO⁻ is a strong base and the best nucleophile of the three.
