146746-58-9Relevant academic research and scientific papers
Palladium-catalyzed asymmetric synthesis of silicon-stereogenic dibenzosiloles via enantioselective C-H bond functionalization
Shintani, Ryo,Otomo, Haruka,Ota, Kensuke,Hayashi, Tamio
supporting information; experimental part, p. 7305 - 7308 (2012/06/16)
A Pd-catalyzed asymmetric synthesis of Si-stereogenic dibenzosiloles is developed through enantioselective C-H bond functionalization of prochiral 2-(arylsilyl)aryl triflates. High chemo- and enantioselectivities are achieved by employing a Josiphos-type ligand under mild conditions.
Enantioselective synthesis of spirocyclic aminochroman derivatives according to the CN(R,S) strategy
Pave, Gregoire,Leger, Jean-Michel,Jarry, Christian,Viaud-Massuard, Marie-Claude,Guillaumet, Gerald
, p. 1401 - 1408 (2007/10/03)
Enantiomerically pure (3′R)- and (3′S)-3′,4′-dihydrospiro[piperidine-2,3′ (2′H)-benzopyran]s (R)-10 and (S)-10 were successfully synthesized according to the CN(R,S) methodology with the aim of serving as a pattern for the generation of related spirocyclic compounds. Two different synthetic pathways were studied starting from 2-cyano-6-phenyloxazolopiperidine (-)-2. One of them was selected and used for the preparation of amines (R)-17 and (S)-17 starting from (-)-2 and (+)-2, respectively. The enantiomeric purity of all final aminochroman derivatives was determinated by capillary electrophoresis using β-cyclodextrin as the chiral selector.
Studies toward the total synthesis of popolohuanone E: enantioselective synthesis of 8-O-methylpopolohuanone E.
Katoh,Nakatani,Shikita,Sampe,Ishiwata,Ohmori,Nakamura,Terashima
, p. 2701 - 2704 (2007/10/03)
[structure: see text]. 8-O-methylpopolohuanone E (2) was synthesized in a highly convergent manner starting from the cis-fused decalin derivative accessible from the (-)-Wieland-Miescher ketone analogue. The synthetic method features a biogenetic-type annulation of the phenolic and quinone segments to regioselectively construct the central tricyclic ring system as the key step.
An Intramolecular Arene-Triflate Coupling Reaction for the Regiospecific Synthesis of Substituted Benzofluoranthenes
Rice, Joseph E.,Cai, Zhen-Wei
, p. 1415 - 1424 (2007/10/02)
An intramolecular triflate-arene coupling reaction mediated by bis(triphenylphosphine)palladium(II) chloride has been developed for the synthesis of each of the isomeric benzofluoranthenes.This reaction, which results in formation of a new five-membered ring, proceeds in highest yields when performed using 0.1 equiv of the palladium catalyst, 3 eqiv of lithium chloride, and 1.2 eqiv of 1,8-diazabicycloundec-7-ene in N,N-dimethylformamide at 140 deg C.The biaryl precursors needed for the coupling reaction can be prepared by nickel(II) chloride catalyzed coupling of an aryl bromide with an magnesium bromide (prepared by ortho-lithiation of an aryl methoxymethyl ether followed by transmetalation with magnesium bromide).Using this procedure benzofluoranthene, benzofluoranthene, benzofluoranthene, and benzofluoranthene were prepared in yields of 84percent, 85percent, 93percent and 64percent, respectively.The reaction to prepare benzofluoranthene was regiospecific and afforded none of the six-membered ring product, perylene.This method was extended to the preparation of benzofluoranthene (BbF) derivatives with fluoro or methoxy groups on the benzo ring.The cyclization of compounds posessing a methoxy group on the same ring as the triflate required the addition of 0.4 equiv of triphenylphosphine to the reaction mixture.Strategies are reported for the regiospecific preparation of 4-, 5-, 6-, and 7-substituted benzofluoranthenes.Evidence is presented wich suggests the intermediacy of radicals in the oxidative-addition of aryl triflates to the palladium catalyst.
