870137-19-2Relevant academic research and scientific papers
Reactions of carbon nucleophiles with 2,2,3-trisubstituted ethynylaziridines
Kelley, Brandon T.,Joullie, Madeleine M.
, p. 1233 - 1239 (2013/10/22)
Carbon nucleophiles were used to open a 2,2,3-trisubstituted ethynylaziridine. A cyanide nucleophile opened the ring at the more substituted carbon, proceeding regioselectively with inversion of configuration. In an attempt to expand upon the scope of the reaction, Normant cuprates were reacted with a 2,2,3-trisubstituted ethynylaziridine. This reaction produced chiral allenes via an anti-SN2′ pathway. X-ray analysis of a derivative allowed the absolute stereochemistry of the anti-allenes to be assigned as P.
Evolution of the total syntheses of ustiloxin natural products and their analogues
Li, Pixu,Evans, Cory D.,Wu, Yongzhong,Cao, Bin,Hamel, Ernest,Joullie, Madeleine M.
, p. 2351 - 2364 (2008/09/20)
Ustiloxins A-F are antimitotic heterodetic cyclopeptides containing a 13-membered cyclic core structure with a synthetically challenging chiral tertiary alkyl-aryl ether linkage. The first total synthesis of ustiloxin D was achieved in 31 linear steps using an SNAr reaction. An NOE study of this synthetic product showed that ustiloxin D existed as a single atropisomer. Subsequently, highly concise and convergent syntheses of ustiloxins D and F were developed by utilizing a newly discovered ethynyl aziridine ring-opening reaction in a longest linear sequence of 15 steps. The approach was further optimized to achieve a better macrolactamization strategy. Ustiloxins D, F, and eight analogues (14-MeO-ustiloxin D, four analogues with different amino acid residues at the C-6 position, and three (9R,10S)-epi-ustiloxin analogues) were prepared via the second-generation route. Evaluation of these compounds as inhibitors of tubulin polymerization demonstrated that variation at the C-6 position is tolerated to a certain extent. In contrast, the S configuration of the C-9 methylamino group and a free phenolic hydroxyl group are essential for inhibition of tubulin polymerization.
The enantioselective synthesis of phomopsin B
Grimley, Joshua S.,Sawayama, Andrew M.,Tanaka, Hiroko,Stohlmeyer, Michelle M.,Woiwode, Thomas F.,Wandless, Thomas J.
, p. 8157 - 8159 (2008/09/18)
Proven approach to a family of antimitotics: The total synthesis of phomopsin B, an antimitotic natural product, was achieved by assembling two fragments of equal complexity in a longest linear sequence of 26 steps. The approach features two catalytic tra
A regio- and stereoselective approach to quaternary centers from chiral trisubstituted aziridines
Forbeck, Erin M.,Evans, Cory D.,Gilleran, John A.,Li, Pixu,Joullie, Madeleine M.
, p. 14463 - 14469 (2008/09/17)
A thorough investigation of a regio- and stereospecific aziridine ring opening reaction presents new synthetic technology for the construction of a variety of quaternary β-substituted-α-amino functional groups. Mild, metal-free reaction conditions allow f
A convergent total synthesis of ustiloxin D via an unprecedented copper-catalyzed ethynyl aziridine ring-opening by phenol derivatives
Li, Pixu,Evans, Cory D.,Joullie, Madeleine M.
, p. 5325 - 5327 (2007/10/03)
(Chemical Equation Presented) The ustiloxins are a family of heterodetic cyclopeptides that have been isolated from the water extracts of false smut balls on the panicles of rice plants caused by the fungus Ustilaginoidea virens. A concise total synthesis of ustiloxin D has been achieved via an unprecedented ethynyl aziridine ring-opening of phenol derivatives. The longest linear sequence of the synthesis is 15 steps from commercially available compounds.
