A Stereoselective Synthesis of (−)-Viridiofungin A Utilizing a TiCl4-Promoted Asymmetric Multicomponent Reaction
摘要:
A stereoselective synthesis of (-)-viridiofungin A is described. The convergent synthesis utilized a unique highly diastereoselective multicomponent reaction between optically active phenyldihydrofuran and an beta-ketoester to provide two chiral centers including a quarternary carbon center in a single step. Other key steps include an acyloxycarbonium ion-mediated tetrahydrofuran ring-opening reaction and a Julia-Kocienski olefination.
Palladium complexes with chiral imidazole ligands as potential catalysts for asymmetric CC coupling reactions
作者:Wojciech Zawartka、Andrzej Gniewek、Anna M. Trzeciak
DOI:10.1016/j.ica.2016.05.021
日期:2017.1
of the type [Pd(im)2Cl2] containing chiral imidazole ligands (im = 1-bornyloxymethylene imidazole, 1-fenchyloxymethylyne imidazole) were synthesized and structurally characterized. The square planar structure of one of the complexes was confirmed by the X-ray analysis. The new palladium complexes were tested as catalysts in various C C bond forming reactions, namely Suzuki–Miyaura, carbonylative Suzuki–Miyaura
C1-symmetric chiral bisphosphine, FcPh-Binap (1), which possesses a single diferrocenylphosphino moiety together with a conventional Ph2P-substituent, was prepared in enantiomericallypure forms. Ligand 1 is sterically less demanding than Fc-Segphos (A), which has two diferrocenylphosphino groups, and showed higher activity than A in the rhodium-catalyzed asymmetric conjugate addition of phenylboronic
Palladium-catalyzed asymmetric Heck arylation of 2,3-dihydrofuran – effect of prolinate salts
作者:Adam Morel、Ewelina Silarska、Anna M. Trzeciak、Juliusz Pernak
DOI:10.1039/c2dt31672b
日期:——
Chiral ionic liquids (CILs) containing L-prolinate and L-lactate anions and non-chiral quaternary ammonium cations were employed in the palladium catalyzed enantioselective Heckarylation of 2,3-dihydrofuran with aryl iodides (iodobenzene, 4-iodotoluene, 2-iodoanisole, 4-iodoanisole, 4-iodoacetophenone). In all the reactions 2-aryl-2,3-dihydrofuran (3) was obtained as the main product with the yield
Synthesis, characterization and first application of chiral <i>C</i>
<sub>2</sub>
-symmetric bis(phosphinite)-Pd(II) complexes as catalysts in asymmetric intermolecular Heck reactions
A series of new chiral C2‐symmetric bis(phosphinite) ligands and their palladium(II) complexes have been synthesized and for the first time used as catalysts in the palladium‐catalysedasymmetric intermolecular Heck coupling reactions of 2,3‐dihydrofuran with iodobenzene or aryl triflate. Under optimized conditions, products were obtained with high conversions and moderate to good enantioselectivities
Enantio- and Regioselective Heck-Type Reaction of Arylboronic Acids with 2,3-Dihydrofuran
作者:Liza Penn、Alina Shpruhman、Dmitri Gelman
DOI:10.1021/jo070170v
日期:2007.5.1
Reported herein is a protocol for the enantioselective Pd(II)-catalyzed Heck-typereaction between arylboronicacids and 2,3-dihydrofuran. The highest chemical and optical yields were obtained when a Pd(OAc)2/(R)-MeO(biphenylphosphine) or a Pd(OAc)2/(R)-(2,2‘-bis(diphenylphosphino)-1,1‘-binaphthyl) catalyst and a Cu(OAc)2 reoxidant were employed.