Thiourea-catalyzed asymmetric domino Michael-cyclization reaction of 3-isothiocyanato oxindoles with β,γ-unsaturated α-keto esters for the synthesis of spirocyclic oxindoles
A reaction between 3-isothiocyanato oxindoles and β,γ-unsaturated α-ketoesters catalyzed by a chiral thiourea organocatalyst via a domino Michael-cyclization process is described, which delivers a range of biologically important 2′-thioxospiro[indoline-3,4′-oxazolidin]-2-one compounds in high yields with good diastereo- and enantioselectivities (up to 99% yield, >99:1 dr, >99% ee). Moreover, two of
Zinc-Catalyzed Enantioselective Dearomative [3+2] Cycloaddition Reaction of 3-Nitrobenzothiophenes and 3-Nitrothieno[2,3-<i>b</i>]yridine with 3-Isothiocyanato Oxindoles
enantioselective dearomative [3+2] cycloadditionreaction of 3‐nitrobenzothiophenes and 3‐nitrothieno[2,3‐b]with 3‐isothiocyanato oxindoles is developed. The reaction is catalyzed by the chiral Zn(OTf)2/bis(oxazoline, and is the second example of a catalytic asymmetric dearomative cycloadditionreaction of 3‐nitrobenzothiophene derivatives. A range of complex heterocyclic compounds containing three contiguous
开发了3-硝基苯并噻吩和3-硝基噻吩并[2,3- b ]与3-异硫氰酸根合吲哚的非对映选择性和对映选择性的[3 + 2]环加成反应。该反应由手性Zn(OTf)2 /双(恶唑啉)催化,是3-硝基苯并噻吩衍生物催化不对称脱芳香环加成反应的第二个例子,一系列复杂的杂环化合物包含三个连续的立体中心,其中一个是螺环中心可以定量获得,且具有优异的立体选择性。
Organocatalytic asymmetric [3+2]-cycloaddition of 3-isothiocyanato oxindoles with 1,3,5-trisubstituted-hexahydro-1,3,5-triazines to access spiro-imidazolidinethione-oxindoles
An efficient asymmetric [3 + 2]-cycloaddition reaction of 3-isothiocyanatooxindoles and formaldimines in-situ generated from 1,3,5-trisubstituted-hexahydro-1,3,5-triazines with a cinchona alkaloid-derived thiourea as the catalyst has been developed. A range of biologically important spiro-imidazolidinethione-oxindoles were obtained in excellent yields with good enantioselectivities (up to 99% yield