134515-52-9Relevant academic research and scientific papers
Dramatic Effect of γ-Heteroatom Dienolate Substituents on Counterion Assisted Asymmetric Anionic Amino-Cope Reaction Cascades
Das, Pradipta,Delost, Michael D.,Qureshi, Munaum H.,Bao, Jianhua,Fell, Jason S.,Houk, Kendall N.,Njardarson, Jon T.
, p. 5793 - 5804 (2021/05/07)
We report a dramatic effect on product outcomes of the lithium ion enabled amino-Cope-like anionic asymmetric cascade when different γ-dienolate heteroatom substituents are employed. For dienolates with azide, thiomethyl, and trifluoromethylthiol substituents, a Mannich/amino-Cope/cyclization cascade ensues to form chiral cyclohexenone products with two new stereocenters in an anti-relationship. For fluoride-substituted nucleophiles, a Mannich/amino-Cope cascade proceeds to afford chiral acyclic products with two new stereocenters in a syn-relationship. Bromide- and chloride-substituted nucleophiles appear to proceed via the same pathway as the fluoride albeit with the added twist of a 3-exo-trig cyclization to yield chiral cyclopropane products with three stereocenters. When this same class of nucleophiles is substituted with a γ-nitro group, the Mannich-initiated cascade is now diverted to a β-lactam product instead of the amino-Cope pathway. These anionic asymmetric cascades are solvent- and counterion-dependent, with a lithium counterion being essential in combination with etheral solvents such as MTBE and CPME. By altering the geometry of the imine double bond from E to Z, the configurations at the R1 and X stereocenters are flipped. Mechanistic, computational, substituent, and counterion studies suggest that these cascades proceed via a common Mannich-product intermediate, which then proceeds via either a chair (X = N3, SMe, or SCF3) or boat-like (X = F, Cl, or Br) transition state to afford amino-Cope-like products or β-lactam in the case of X = NO2.
Microwave-assisted InCl3-catalyzed Meyer-Schuster rearrangement of propargylic aryl carbinols in aqueous media: a green approach to α,β-unsaturated carbonyl compounds
Cadierno, Victorio,Francos, Javier,Gimeno, José
experimental part, p. 4773 - 4776 (2011/03/19)
A novel, efficient, simple and environmentally benign protocol for the Meyer-Schuster isomerization of propargylic aryl carbinols into α,β-unsaturated carbonyl compounds has been developed using catalytic amounts of InCl3, pure water as the solvent, and microwave irradiation as the heating source.
Synthesis and antifungal activities of R-102557 and related dioxane- triazole derivatives
Oida, Sadao,Tajima, Yawara,Konosu, Toshiyuki,Nakamura, Yoshie,Somada, Atsushi,Tanaka, Teruo,Habuki, Shinobu,Harasaki, Tamako,Kamai, Yasuki,Fukuoka, Takashi,Ohya, Satoshi,Yasuda, Hiroshi
, p. 694 - 707 (2007/10/03)
Novel triazole compounds with a dioxane ring were synthesized. Condensation of the diol precursor 10 with various aromatic aldehydes 11 - 13 under acidic conditions afforded a series of dioxane-triazole compounds 14 - 16. The antifungal activities of the compounds 14 - 16 were evaluated in vivo in mice infection models against Candida and Aspergillus species. High activities were seen for the derivatives with one or two double bond(s) and an aromatic ring substituted with an electron-withdrawing group in the side chain. Among the derivatives, R-102557 (16R: Ar=4-(2,2,3,3- tetrafluoropropoxy)phenyl) showed excellent in vivo activities against Candida, Aspergillus and Cryptococcus species. It also showed high tolerance in a preliminary toxicity study in rats.
