Coibamide A, a potent antiproliferative cyclic depsipeptide from the panamanian marine cyanobacterium Leptolyngbya sp.
Coibamide A (1) is a new, potent antiproliferative depsipeptide which was isolated from a marine Leptolyngbya cyanobacterium collected from the Coiba National Park, Panama. The planar structure of 1 was elucidated by a combination of NMR spectroscopy and mass spectrometry. Exhaustive 1D and 2D NMR spectroscopy included natural abundance 15N and variable temperature experiments; mass spectrometry included TOF-ESI-MSn and FT-MSn experiments. Chemical degradation followed by chiral HPLC- and GC-MS analyses was used to assign the absolute configuration of 1. This highly methylated cyclized depsipeptide exhibited an unprecedented selectivity profile in the NCI 60 cancer cell line panel and appears to act via a novel mechanism. Copyright
Medina, Rebecca A.,Goeger, Douglas E.,Hills, Patrice,Mooberry, Susan L.,Huang, Nelson,Romero, Luz I.,Ortega-Barria, Eduardo,Gerwick, William H.,McPhail, Kerry L.
Asymmetric synthesis catalyzed by chiral ferrocenylphosphine transition metal complexes. 10 gold(I)-catalyzed asymmetric aldol reaction of isocyanoacetate
Optically active ferrocenylbisphosphine ligands containing 2-(dialkylamino)ethylamino group on the ferrocenylmethyl position have been prepared and used for the gold(I)-catalyzed asymmetric aldol reaction of isocyanoacetate with aldehydes. Six-membered ring amines, such as morpholino or piperidino group, at the terminal of the side chain were most stereoselective to give optically active trans-4- methoxycarbonyl-5-alkyl-2-oxazolines (up to 97% ee) with high enantio- and diastereoselectivity in a quantitative yield.
Hayashi, Tamio,Sawamura, Masaya,Ito, Yoshihiko
p. 1999 - 2012
(2007/10/02)
ASYMMETRIC ALDOL REACTION OF α-ISOCYANOACETAMIDES WITH ALDEHYDES CATALYZED BY A CHIRAL FERROCENYLPHOSPHINE-GOLD(I) COMPLEX
Aldol reaction of N,N-dialkyl-α-isocyanoacetamides with primary alkyl aldehydes in the presence of 0.5-1 molpercent of a chiral (aminoalkyl)ferrocenylphosphine-gold(I) catalyst proceeded with high enantio- and diastereoselectivity to give trans-5-alkyl-2-oxazoline-4-carboxamides of up to 98.6percent ee, which were converted into optically active threo-β-hydroxyamino acids.
ASYMMETRIC ALDOL REACTION OF AN ISOCYANOACETATE WITH ALDEHYDES CATALYZED BY CHIRAL FERROCENYLPHOSPHINE-GOLD(I) COMPLEXES: DESIGN AND PREPARATION OF NEW EFFICIENT FERROCENYLPHOSPHINE LIGANDS
An optically active ferrocenylphosphine ligand containing 2-(morpholino)ethylamino or 2-(piperidino)ethylamino group on the ferrocene side chain was effective for the goldcatalyzed aldol reaction of methyl isocyanoacetate with aldehydes to give optically active 4-methoxycarbonyl-5-alkyl-2-oxazolines (up to 96 percent ee) with high enantio- and diastereoselectivity in a quantitative yield.
Ito, Yoshihiko,Sawamura, Masaya,Hayashi, Tamio
p. 6215 - 6218
(2007/10/02)
Catalytic Asymmetric Aldol Reaction: Reaction of Aldehydes with Isocyanoacetate Catalyzed by a Chiral Ferrocenylphosphine-Gold(I) Complex
-
Ito, Yoshihiko,Sawamura, Masaya,Hayashi, Tamio
p. 6405 - 6406
(2007/10/02)
More Articles about upstream products of 104320-71-0