Abstract The electronic effect of alkyl groups is a core concept throughout the organic chemistry curriculum. For a long time, many domestic textbooks have simplistically described alkyl groups as having an electron-donating inductive effect (+I). This statement essentially mistakes the overall electronic effect of alkyl groups for their inductive effect. Extensive experimental studies and theoretical calculations have confirmed that, compared to a hydrogen atom, alkyl groups inherently possess an electron-withdrawing inductive effect (-I); their apparent electron-donating character stems primarily from the electron-donating hyperconjugative effect (+R). This article systematically reviews the experimental and theoretical evidence for the electron-withdrawing inductive effect of alkyl groups, analyzes the logical contradictions in common textbook descriptions, and provides explanations based on the “-I+R” model for teaching challenges such as the stability of carbocations, the acidity/basicity of alcohols and amines, and the substituent effects on aromatic rings and carbonyl groups. It is recommended that teaching and textbook writing strictly distinguish between the inductive effect and the overall electronic effect of alkyl groups, clarifying their “-I+R” electronic nature to establish a more accurate and self-consistent knowledge framework.
YAO Qiu-Li. Discussion on the Electron Withdrawing Inductive Effect and Substituent Effects of Alkyl Group[J]. Chinese Journal of Chemical Education, 2026, 47(16): 109-114.
