16206-89-6Relevant academic research and scientific papers
Modular total synthesis of rhizopodin: A highly potent G-actin dimerizing macrolide
Kretschmer, Manuel,Dieckmann, Michael,Li, Pengfei,Rudolph, Sven,Herkommer, Daniel,Troendlin, Johannes,Menche, Dirk
supporting information, p. 15993 - 16018 (2014/04/03)
A highly convergent total synthesis of the potent polyketide macrolide rhizopodin has been achieved in 29steps by employing a concise strategy that exploits the molecule′s C2 symmetry. Notable features of this convergent approach include a rapid assembly of the macrocycle through a site-directed sequential cross-coupling strategy and the bidirectional attachment of the side chains by means of Horner-Wadsworth-Emmons (HWE) coupling reactions. During the course of this endeavor, scalable routes for synthesis of three main building blocks of similar complexity were developed that allowed for their stereocontrolled construction. This modular route will be amenable to the development of syntheses of other analogues of rhizopodin.
One-pot organocatalytic domino michael/α-alkylation reactions: Direct catalytic enantioselective cyclopropanation and cyclopentanation reactions
Ibrahem, Ismail,Zhao, Gui-Ling,Rios, Ramon,Vesely, Jan,Sunden, Henrik,Dziedzic, Pawel,Cordova, Armando
experimental part, p. 7867 - 7879 (2009/09/06)
The development of one-pot organocatalytic domino Michael/α- alkylation reactions between bromomalonates or bromoacetoacetate esters and α,β-unsaturated aldehydes is presented. The chiral-amine-catalyzed reactions with bromomalonates as substrates give access to the corresponding 2-formylcyclopropane derivatives in high yields with excellent diastereoselectivity and up to 99% ee. The catalytic domino Michael/α- alkylation reactions between 4-bromo-acetoacetate and enals provide a route for the synthesis of functionalized cyclopentanones in good to high yields with 93-99 % ee. The products from the organocatalytic reactions were also reduced with high diastereoselectivity to the corresponding cyclopropanols and cy-clopentanols, respectively. Moreover, one-pot combinations of amine and heterocyclic carbene catalysis (AHCC) enabled the highly enantioselective synthesis of β-malonate esters (91-97% ee) from the reaction between bromomalonates and enals. The tandem catalysis included the catalytic domino reaction followed by catalytic in situ chemoselective ring-opening of the 2-formylcyclopropane intermediates.
Complexes of borane and N-heterocyclic carbenes: A new class of radical hydrogen atom donor
Ueng, Shau-Hua,Brahmi, Malika Makhlouf,Derat, Etienne,Fensterbank, Louis,Lacote, Emmanuel,Malacria, Max,Curran, Dennis P.
supporting information; scheme or table, p. 10082 - 10083 (2009/02/04)
Calculations suggest that complexes of borane with N-heterocyclic carbenes (NHC) have B-H bond dissocation energies more then 20 kcal/mol less than free borane, diborane, borane-THF, and related complexes. Values are in the range of popular radical hydrogen atom donors like tin hydrides (70-80 kcal/mol). The resulting prediction that NHC borane complexes could be used as radical hydrogen atom donors was verified by radical deoxygenations of xanthates by using either AIBN or triethylborane as initiator. Copyright
Catalytic generation of activated carboxylates: Direct, stereoselective synthesis β-hydroxyesters from epoxyaldehydes
Chow, Kenneth Yu-Kin,Bode, Jeffrey W.
, p. 8126 - 8127 (2007/10/03)
The catalytic generation of activated carboxylates from epoxyaldehydes enables the direct, stereoselective synthesis of β-hydroxyesters under mild, convenient reaction conditions. In addition to providing a new method for the synthesis of anti-aldol adducts, this chemistry unveils a mechanistically viable solution to the catalytic, waste-free synthesis of esters. Copyright
