137105-58-9Relevant academic research and scientific papers
Total Synthesis of (±)-Impatien A via Aza-Heck Cyclization
Korch, Katerina M.,Watson, Donald A.
, p. 7285 - 7289 (2021/09/14)
The first total synthesis of the natural product impatien A is described. This concise synthesis features an aza-Heck cyclization to construct the complex spirocyclic ring system and provides a rare example of the use of aza-Heck cyclizations in complex molecule synthesis. To enable this key cyclization of an electrophilic nitrogen atom with a tetrasubstituted alkene, we utilized high-throughput experimentation to identify a new ligand and ultimately deliver impatien A in seven steps from known compounds.
Electrophilic C12 building blocks for alkaloids: 1,1 iterative organoiron-mediated routes to (±)-lycoramine and (±)-maritidine
Stephenson, G. Richard,Roe, Caroline,Sandoe, Elizabeth J.
experimental part, p. 1664 - 1681 (2011/05/15)
Aryllithium reagents generated from protected 6-bromoguaiacol and 2-bromo-4,5-dimethoxybenzyl alcohol derivatives were used to prepare ortho-substituted (1-arylcyclohexadienyl)iron(1+) electrophiles. These were treated with Na+[Me3SiCH2CH2O 2CCHCN]- to build aryl-substituted quaternary centres in new examples of 1,1 iterative {[I·4] → [I·5]+ → [I·4] → [I·5]+ → [I· 4]} reaction sequences, which make use of the electrophilicity of the metal complex in two key carbon-carbon bond-formation steps. MOM protection of the guaiacol was better than SEM for access to the lycoramine skeleton, and TBDPS was best for maritidine. Decomplexation, hydrolysis, and cyclisation completed formal total syntheses of the Amaryllidaceae alkaloids (±)-lycoramine and (±)-marididine, establishing the compatibility of the organoiron method with the presence of ortho substituents on the aryl group, and nucleophile addition ipso to the substituted arene. Copyright
Diversity oriented microwave-assisted synthesis of (-)-steganacin aza-analogues
Mont, Nuria,Mehta, Vaibhav Pravinchandra,Appukkuttan, Prasad,Beryozkina, Tetyana,Toppet, Suzzane,Van Hecke, Kristof,Van Meervelt, Luc,Voet, Arnout,DeMaeyer, Marc,Van Der Eycken, Erik
, p. 7509 - 7516 (2008/12/22)
(Chemical Equation Presented) A novel microwave-assisted, highly efficient protocol for the synthesis of hitherto unknown aza-analogues of (-)-Steganacin, a naturally occurring bisbenzocyclooctadiene lignan lactone with potent antileukemic and tubulin polymerization inhibitory activity, has been developed. Focused microwave irradiation is demonstrated to be highly beneficial in promoting the three crucial steps of the sequence to effect the final ring closure: the Suzuki-Miyaura reaction, Cu-mediated A3-coupling, as well as the intramolecular Huisgen 1,3-dipolar cycloaddition.
Microwave-enhanced synthesis of new (-)-steganacin and (-)-steganone aza analogues
Beryozkina, Tetyana,Appukkuttan, Prasad,Mont, Nuria,Van Der Eycken, Erik
, p. 487 - 490 (2007/10/03)
A novel, microwave-enhanced, highly efficient protocol for the synthesis of hitherto unknown (-)-steganacin and (-)-steganone 7-aza analogues containing a 1,2,3-triazole ring has been presented. Microwave irradiation was found to be highly beneficial in promoting the Suzuki reaction and the 1,3-dipolar cycloaddition reaction to generate the highly strained medium-sized ring system of the title molecules.
Intermolecular silyl migration reactions
Rodriguez, Carolina,Garcia, Antonio G.,Marco-Contelles, Jose
, p. 698 - 701 (2007/10/03)
Sodium hydride promoted O-alkylation of 2-[(4-t-butyldimethylsilyloxy) phenyl]ethan-1-ol with 1-bromo-2-(bromomethyl)-4,5-dimethoxybenzene depend on the solvent used in the coupling reaction. Mixtures of 2-[4-(2-bromo-4,5- dimethoxybenzyloxy)phenyl]-1-t-butyldimethylsilyloxyethaneand2-[4-(2-bromo-4, 5-dimethoxybenzyloxy)phenyl] ethan-1-ol (in DMF), or 2-[4-(2-bromo-4,5- dimethoxybenzyloxy)phenyl]-1-t-butyldimethylsilyloxyethane and 4-[2-(2-bromo-4,5-dimethoxybenzyloxy)ethyl]phenol (in THF), were detected. These results can be explained by an unusual intermolecular silyl migration reaction.
Rotenoid Synthesis by Wadsworth-Emmons Coupling and Mukaiyama Cyclisation: Application to 5-Thiorotenoids
crombie, Leslie,Josephs, Jonathan L.
, p. 2599 - 2604 (2007/10/02)
A new synthesis of general applicability to rotenoid structures is described, through its specific objectives were 5-thiorotenoids.The synthons carrying the A/B- and the B/C-ring components are coupled by Wadsworth-Emmons synthesis and the ring B chromene is formed by Mukaiyama directed aldol cylisation: Michael addition completes the formation of the rotenoid at its correct oxidation state and in its stable cis-form.Examples with, and without 2,3-dimethoxylation in ring A are described.
