title: Direct catalytic asymmetric synthesis of highly functionalized (2-ethynylphenyl)alcohols via Barbas-List aldol reaction: scope and synthetic applications.
abstract: A high-yielding asymmetric synthesis of functionalized (2-ethynylphenyl)alcohols 5/6 with good diastereo- and enantioselectivities was achieved by Barbas-List aldol (BLA) reaction of 2-alkynylbenzaldehydes 1 with various ketones 2 in the presence of trans-4-OH-L-proline or L-prolinamide derivative 3/4 as catalyst at the ambient temperature or -35 °C. This method also gives first time access to the novel double aldol addition compounds 6, which are of medicinal importance. Chiral functionalized (2-ethynylphenyl)alcohols 5/6 were transformed into acyclic and cyclic 1,4-triazoles 8/9 and cis-1,3-diols 10 in good yields with high selectivity through double click-reaction and Lewis acid-mediated NaBH(4) reduction respectively. Chiral products 8-10 may become good ligands and inhibitors in medicinal chemistry.
authors.affiliation: Catalysis Laboratory, School of Chemistry, University of Hyderabad, Hyderabad-500 046, India. ramsc@uohyd.ernet.in
authors.forename: Dhevalapally B
authors.initials: DB
authors.lastname: Ramachary
authors.forename: Rumpa
authors.initials: R
authors.lastname: Mondal
authors.forename: R
authors.initials: R
authors.lastname: Madhavachary
mesh_terms: D000438:Alcohols / Q000138:chemical synthesis* / Q000737:chemistry; D000447:Aldehydes / Q000138:chemical synthesis / Q000737:chemistry*; D001547:Benzaldehydes / Q000138:chemical synthesis / Q000737:chemistry; D002384:Catalysis; D057930:Click Chemistry; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry; D008958:Models, Molecular; D011392:Proline / Q000031:analogs & derivatives / Q000138:chemical synthesis; D013237:Stereoisomerism; D014230:Triazoles / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D000438:Alcohols; D000447:Aldehydes; D001547:Benzaldehydes; D007659:Ketones; D014230:Triazoles; C116609:3-hydroxybutanal; D011392:Proline