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Cover Image, Volume 35, Issue 5
Publication year - 2014
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Reports
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.23531
Subject(s) - lone pair , cover (algebra) , maleic anhydride , cyclopentadiene , steric effects , chemistry , cycloaddition , moiety , stereochemistry , molecule , organic chemistry , mechanical engineering , engineering , copolymer , catalysis , polymer
The endo selectivity of the archetypal Diels–Alder cycloaddition between cyclopentadiene and maleic anhydride is caused by an unfavorable steric arrangement in the transition‐state region of the exo pathway, as shown on the back cover. The methylene moiety of cyclopentadiene runs into the oxygen lone‐pair electrons of maleic anhydride, which translates into a more destabilizing activation strain. Neither the donor–acceptor orbital interactions nor the total interaction between the deformed reactants contributes to the endo selectivity, as detailed by Israel Fernández and F. Matthias Bickelhaupt on page 371 .