The totalsynthesis of the smallest cytochalasin isolated so far, periconiasin G, which bears a seven‐membered ring in lieu of the usual macrocycle, has been performed from both enantiomers of citronellal, relying on an intramolecular Diels–Alder reaction in favor of the natural endo stereochemistry. We show that, among the four synthesized stereoisomers, including the exo isomers, the one matching
The first and collective totalsyntheses of periconiasins A–E, a group of naturally occurring cytochalasans, were achieved by a series of rationally designed or bioinspired transformations. Salient features of the syntheses include a tandem aldol condensation/Grob fragmentation to assemble the linear polyketide–amino acid hybrid precursor, a Diels–Alder macrocylization to construct the 9/6/5 tricyclic
Highly Diastereoselective Addition of the Lithium Enolate of α-Diazoacetoacetate to <i>N</i>-Sulfinyl Imines: Enantioselective Synthesis of 2-Oxo and 3-Oxo Pyrrolidines
作者:Changqing Dong、Fanyang Mo、Jianbo Wang
DOI:10.1021/jo702275a
日期:2008.3.1
The highly enantioselective synthesis of 2-oxo and 3-oxo pyrrolidines has been achieved by diastereoselective addition of the lithiumenolate of α-diazoacetoacetate to chiral N-sulfinyl imines, followed by photoinduced Wolff rearrangement or Rh(II)-catalyzed intramolecular N−H insertion.
Enantioselective Intermolecular Enamide–Aldehyde Cross-Coupling Catalyzed by Chiral <i>N</i>-Heterocyclic Carbenes
作者:Jicheng Wu、Changgui Zhao、Jian Wang
DOI:10.1021/jacs.5b13501
日期:2016.4.13
carbene (NHC)-catalyzed intermolecular cross-coupling of enamides and aldehydes is described. Upon exposure of enamides to aldehydes in the presence of a NHC catalyst, catalytic C-C bond formation occurs, providing highly enantioselective N-protected amines, bearing a quaternary carboncenter, in good yields and with high enantioselectivities.
描述了前所未有的 N-杂环卡宾 (NHC) 催化的烯酰胺和醛的分子间交叉偶联。在 NHC 催化剂存在下将烯酰胺暴露于醛后,会发生催化 CC 键的形成,提供高度对映选择性的 N 保护胺,带有季碳中心,收率高,对映选择性高。
Discovery of Indolinone-Based Multikinase Inhibitors as Potential Therapeutics for Idiopathic Pulmonary Fibrosis
Idiopathicpulmonaryfibrosis (IPF) is a serious and deadly disease for which treatment options are limited. The recent approval of antifibrosis agent nintedanib represents one of the first therapeutic approaches for the treatment of IPF. Here, we report novel indolinone-based multikinase inhibitors that target angiogenesis and fibrosis pathways and may serve as potential therapeutics for IPF. KBP-7018