223751-48-2Relevant articles and documents
Palladium-Catalyzed, tert-Butyllithium-Mediated Dimerization of Aryl Halides and Its Application in the Atropselective Total Synthesis of Mastigophorene A
Buter, Jeffrey,Heijnen, Dorus,Vila, Carlos,Hornillos, Valentín,Otten, Edwin,Giannerini, Massimo,Minnaard, Adriaan J.,Feringa, Ben L.
, p. 3620 - 3624 (2016/03/23)
A palladium-catalyzed direct synthesis of symmetric biaryl compounds from aryl halides in the presence of tBuLi is described. In situ lithium-halogen exchange generates the corresponding aryl lithium reagent, which undergoes a homocoupling reaction with a second molecule of the aryl halide in the presence of the palladium catalyst (1 mol %). The reaction takes place at room temperature, is fast (1 h), and affords the corresponding biaryl compounds in good to excellent yields. The application of the method is demonstrated in an efficient asymmetric total synthesis of mastigophorene A. The chiral biaryl axis is constructed with an atropselectivity of 9:1 owing to catalyst-induced remote point-to-axial chirality transfer. It takes two: A palladium-catalyzed direct homocoupling of aryl halides in the presence of tBuLi enabled the synthesis of even tetra-ortho-substituted symmetric biaryl compounds in high yield (see scheme). The method was applied to the asymmetric synthesis of mastigophorene A in just eight steps through straightforward enantioselective installation of the benzylic quaternary stereocenter and highly diastereoselective homocoupling.
Nondynamic and dynamic kinetic resolution of lactones with stereogenic centers and axes: Stereoselective total synthesis of herbertenediol and mastigophorenes A and B
Bringmann, Gerhard,Pabst, Thomas,Henschel, Petra,Kraus, Juergen,Peters, Karl,Peters, Eva-Maria,Rycroft, David S.,Connolly, Joseph D.
, p. 9127 - 9133 (2007/10/03)
The stereoselective total synthesis of the sesquiterpene herbertenediol (3) and of its naturally occurring dimers, mastigophorenes A [(P)-1] and B [(M)-1], is described. Following the 'lactone concept', the configuration at the biaryl axis was atropo-dive
Total syntheses of (-)-herbertenediol, (-)-mastigophorene A, and (-)- mastigophorene B. Combined utility of chiral bicyclic lactams and chiral aryl oxazolines
Degnan, Andrew P.,Meyers
, p. 2762 - 2769 (2007/10/03)
A nonracemic bicyclic lactam has been used to construct a chiral cyclopentane containing vicinal quaternary carbon centers in optically pure form, which is common to all of the title compounds. An oxazoline-mediated asymmetric Ullmann coupling was then utilized to establish chirality about the biaryl axis of mastigophorenes A and B. Through the course of this synthesis, it was clearly demonstrated that smaller chiral auxiliaries lead to higher levels of atroposelection, a previously unknown phenomenon of the asymmetric Ullmann coupling.
