@article{oai:nagoya.repo.nii.ac.jp:00028694,
 author = {Hatano, Manabu and Sakamoto, Tatsuhiro and Mochizuki, Takuya and Ishihara, Kazuaki},
 issue = {7},
 journal = {Asian Journal of Organic Chemistry},
 month = {Jul},
 note = {In the enantioselective inverse‐electron‐demand hetero‐Diels‐Alder reaction, simple α,β‐unsaturated aldehydes (i. e., acroleins) are still challenging substrates, unlike α,β‐unsaturated carbonyl compounds containing electron‐withdrawing groups. In the present study, the reaction of α‐aryl‐β‐alkyl‐substituted acroleins with ethyl vinyl sulfide was developed with the use of bulky chiral supramolecular Brønsted acid catalysts, such as tris(pentafluorophenyl)borane‐assisted chiral phosphoric acid catalysts. As a result, cis‐cycloadducts as optically active 3,4‐dihydro‐2H‐pyrans were exclusively obtained in high yields with high enantioselectivities via the favored endo orbital approach. An obtained optically active cis‐isomer could be transformed into the corresponding trans‐isomer without a loss of enantiopurity by O,S‐acetal epimerization. Moreover, transformations to synthetically useful optically active epoxide and δ‐valerolactone are also demonstrated., ファイル公開：2020/07/01},
 pages = {1061--1066},
 title = {Tris(pentafluorophenyl)borane‐Assisted Chiral Phosphoric Acid Catalysts for Enantioselective Inverse‐Electron‐Demand Hetero‐Diels‐Alder Reaction of α,β‐Substituted Acroleins},
 volume = {8},
 year = {2019}
}