41894-54-6Relevant academic research and scientific papers
Design of bronsted acid-assisted chiral Lewis acid (BLA) catalysts for highly enantioselective Diels-Alder reactions
Ishihara, Kazuaki,Kurihara, Hideki,Matsumoto, Masayuki,Yamamoto, Hisashi
, p. 6920 - 6930 (1998)
Bronsted acid-assisted chiral Lewis acid (BLA) was highly effective as a chiral catalyst for the enantioselective Diels-Alder reaction of both α- substituted and α-unsubstituted α,β-enals with various dienes. Hydroxy groups in optically active binaphthol derivatives and boron reagents with electron-withdrawing substituents were used as Bronsted acids and Lewis acids, respectively. Intramolecular Bronsted acids in a chiral BLA catalyst played an important role in accelerating the rate of Diels-Alder reactions and in producing a high level of enantioselectivity. In particular, excellent enantioselectivity was achieved due to intramolecular hydrogen bonding interaction and attractive π-π donor-acceptor interaction in the transition-state assembly by hydroxy aromatic groups in a chiral BLA catalyst.
