Organocatalytic Diversity-Oriented Asymmetric Synthesis of Tricyclic Chroman Derivatives

• Published in: Journal of organic chemistry Vol. 79; no. 22; pp. 10772 - 10785
• Main Authors: Geng, Zhi-Cong, Zhang, Shao-Yun, Li, Nai-Kai, Li, Ning, Chen, Jian, Li, Hai-Yan, Wang, Xing-Wang
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 21.11.2014; Amer Chemical Soc
• Subjects: Butyrates - chemistry; Catalysis; Chemistry; Chemistry, Organic; Chromans - chemical synthesis; Chromans - chemistry; Ethers - chemistry; Molecular Structure; Physical Sciences; Pyrrolidines - chemistry; Science & Technology; Stereoisomerism; Trimethylsilyl Compounds - chemistry; TANDEM REACTIONS; CATALYSIS; DOMINO REACTIONS; ENANTIOSELECTIVE SYNTHESIS; DIELS-ALDER REACTION; SENSITIVE POTASSIUM CHANNEL; CASCADE; CHROMENES; DIHYDROCOUMARINS; MICHAEL ADDITION
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo501560m

The tandem oxo-Michael-IED/HDA and oxo-Michael-IED/HDA-Michael-Aldol condensation transformations between (E)-2-hydroxyaryl-2-oxobut-3-enoate derivatives with enals have been developed in the presence of (S)-diphenylprolinol trimethylsilyl ether as an organocatalyst. Two types of tricyclic chroman derivatives were, respectively, obtained, by adjusting the reactant ratio and reaction temperature, in good yields (up to 96%) with excellent enantioselectivities (up to >99%) and good diastereoselectivities (up to >30/1). It should be noted that the divergent chiral chroman derivatives were obtained by successive reaction of (E)-2-hydroxy­aryl-2-oxobut-3-enoate derivatives with two different enal substrates in highly catalytic results.