Synthesis of γ-, δ-, and ε-Lactams by Asymmetric Transfer Hydrogenation of <i>N</i>-(<i>tert</i>-Butylsulfinyl)iminoesters
作者:David Guijarro、Óscar Pablo、Miguel Yus
DOI:10.1021/jo400164y
日期:2013.4.19
Highly enantiomerically enriched γ- and δ-lactams have been prepared by a simple and very efficient procedure that involves the asymmetrictransferhydrogenation of N-(tert-butylsulfinyl)iminoesters followed by desulfinylation of the nitrogen atom and spontaneous cyclization to the desired lactams during the basic workup procedure. Five- and six-membered ring lactams bearing aromatic, heteroaromatic
Enantioselective Organocatalyzed Bromolactonizations: Applications in Natural Product Synthesis
作者:Marius Aursnes、Jørn E. Tungen、Trond V. Hansen
DOI:10.1021/acs.joc.6b01375
日期:2016.9.16
The best catalyst enabled the cyclization of several 5-arylhex-5-enoic acids into the corresponding bromolactones with up to 96% ee and in high to excellent chemical yields. The reported catalysts are prepared in a straightforward manner in two steps from dimethyl squarate. The utility of the developed protocol was demonstrated in highly enantioselective syntheses of the sesquiterpenoids (−)-gossoronol
Enantioselective Synthesis of Indolizidines Bearing Quaternary Substituted Stereocenters via Rhodium-Catalyzed [2 + 2 + 2] Cycloaddition of Alkenyl Isocyanates and Terminal Alkynes
作者:Ernest E. Lee、Tomislav Rovis
DOI:10.1021/ol800086s
日期:2008.3.1
An enantioselectivesynthesis of indolizidines bearing quaternary substituted stereocenters by way of a rhodium-catalyzed [2+2+2] cycloaddition of substituted alkenyl isocyanates and terminal alkynes is described. The reaction provides lactam products using aliphatic alkynes, whereas aryl alkynes give rise to vinylogous amide products. Through modification of the phosphoramidite ligand, high levels
SUBSTITUTED TARAXASTANES USEFUL FOR TREATING VIRAL INFECTIONS
申请人:BRADBURY Barton James
公开号:US20070197646A1
公开(公告)日:2007-08-23
Substituted taraxastanes useful for treating viral infections, are provided herein. Thus, in a first aspect, the invention provides compounds of Formula I
and the pharmaceutically acceptable salts thereof, wherein the variables R
1
, R
2
, and X are defined herein. The compounds described herein are thought to act by inhibiting retroviral maturation, including maturation of encapsulated retroviruses viruses, such as the HIV viruses, HIV-1 and HIV-2. Pharmaceutical compositions comprising such compounds of Formula I are included herein. Methods of using such compounds to treat human patients infected with an HIV virus and reducing the mortality of AIDS are also provided herein.
The apple never falls far from the tree: S‐alkylthiocarbamate 1 (see scheme, NBP=N‐bromophthalimide) was prepared in high yield through a synthetic sequence involving a Newman–Kwart rearrangement of the corresponding O‐alkylthiocarbamates. Compound 1 was used to catalyze bromolactonization, thus providing enantioenriched δ‐lactones in excellent yield and enantioselectivity.