1206146-95-3Relevant academic research and scientific papers
Vicinal bisheterocyclizations of alkynes via nucleophilic interception of a catalytic platinum carbene
Allegretti, Paul A.,Ferreira, Eric M.
, p. 17266 - 17269 (2013)
A novel platinum-catalyzed double heterocyclization of propargylic ethers is described. The transformation exploits the intermediacy of a key α,β-unsaturated carbene. The reactivity of this carbene is such that systems can be developed which avoid a complicating 1,2-hydrogen migration, allowing remarkable versatility in the selective syntheses of oxygen- and nitrogen-containing vicinal bis-heterocyclic compounds.
Unique diastereoselectivity trends in aminyl radical cyclizations onto silyl enol ethers
Zlotorzynska, Maria,Zhai, Huimin,Sammis, Glenn M.
supporting information; experimental part, p. 864 - 872 (2010/05/18)
(Chemical Equation Presented) The cyclization of nitrogen-centered radicals onto silyl enol ethers is an efficient method for the synthesis of polyhydroxylated alkaloids as the 2-hydroxymethylpyrrolidine core can be readily accessed from a linear precursor. During our studies on the synthesis of polyhydroxylated alkaloid CYB-3, we found that the diastereoselectivity of the cyclization was dependent on a complex combination of sterics and olefin geometry. A more thorough understanding of the factors that lead to high diastereoselectivites would greatly expand the utility of this methodology in complex natural product synthesis. We have found that cyclization diastereoselectivities of substrates with alkyl or aryl substitution were excellent regardless of olefin geometry or substitution pattern. When electronegative substituents were introduced adjacent to the silyl enol ether, only Z-silyl enol ethers provide high diastereoselectivites. Temperature, steric size of the silyl group, and sterics and electronics of the metal hydride affected the selectivity to a lesser extent.
Cyclizations of aminyl radicals generated from substoichiometric stannane
Zhai, Huimin,Wickenden, Jason G.,Sammis, Glenn M.
supporting information; experimental part, p. 3035 - 3038 (2011/02/24)
Substoichiometric amounts of tributyltin hydride were utilized in nitrogen-centered radical cyclizations onto silyl enol ethers for the formation of substituted cyclic imines
