title: Chiral squaramide-catalyzed asymmetric synthesis of pyranones and pyranonaphthoquinones via cascade reactions of 1,3-dicarbonyls with Morita-Baylis-Hillman acetates of nitroalkenes.
abstract: Cascade reactions of 1,3-dicarbonyls with Morita-Baylis-Hillman acetates of nitroalkenes using a quinine derived chiral squaramide organocatalyst led to the formation of pyranones and pyranonaphthoquinones in good to excellent yields and high diastereo- and enantioselectivities. Representative examples of the reaction scale-up with a much lower catalyst loading without an appreciable loss of selectivities and synthetic transformations of the products are also reported here. The compounds described herein for the first time were evaluated against the infective bloodstream form of Trypanosoma cruzi, the etiological agent of Chagas disease, since the structures are related to bioactive α-lapachones.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076, India. irishi@iitb.ac.in.
authors.forename: Divya K
authors.initials: DK
authors.lastname: Nair
authors.forename: Rubem F S
authors.initials: RF
authors.lastname: Menna-Barreto
authors.forename: Eufrânio N
authors.initials: EN
authors.lastname: da Silva Júnior
authors.forename: Shaikh M
authors.initials: SM
authors.lastname: Mobin
authors.forename: Irishi N N
authors.initials: IN
authors.lastname: Namboothiri
mesh_terms: D000085:Acetates / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry*; D000818:Animals; D002384:Catalysis; D014355:Chagas Disease / Q000188:drug therapy; D003503:Cyclobutanes / Q000737:chemistry*; D008958:Models, Molecular; D009574:Nitro Compounds / Q000737:chemistry*; D011714:Pyrans / Q000737:chemistry*; D011809:Quinones / Q000737:chemistry*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014344:Trypanocidal Agents / Q000138:chemical synthesis* / Q000494:pharmacology*; D014349:Trypanosoma cruzi
chemical_list: D000085:Acetates; D000475:Alkenes; D003503:Cyclobutanes; D009574:Nitro Compounds; D011714:Pyrans; D011809:Quinones; D014344:Trypanocidal Agents