efficient and catalyticasymmetric alkynylation of isatins has been developed using a bifunctional amidophosphine‐urea/AgBF4 complex as the catalyst. By a combination of metal catalysis and organocatalysis, excellent enantioselectivities (up to 99 % ee) and good yields are achieved. A wide range of both terminal alkynes and isatins are tolerated by this new catalyst system, providing access to structurally
Enantioselective and Regioselective Indium(III)-Catalyzed Addition of Pyrroles to Isatins
作者:Elisa G. Gutierrez、Casey J. Wong、Aziza H. Sahin、Annaliese K. Franz
DOI:10.1021/ol202329s
日期:2011.11.4
The indium(III)-catalyzed enantioselective and regioselectiveaddition of pyrroles to isatins is described. The effects of metal and solvent on the reactivity and selectivity are compared and discussed, demonstrating that the indium(III)–indapybox complex provides the most effective catalyst. A case of divergent reactivity between pyrroles and indoles is presented.
Charting Biologically Relevant Spirocyclic Compound Space
作者:Gerhard Müller、Tim Berkenbosch、Jorg C. J. Benningshof、Dagmar Stumpfe、Jürgen Bajorath
DOI:10.1002/chem.201604714
日期:2017.1.12
there should be significant potential to further expand spirocyclic chemical space for drug discovery, exploiting the privileged substructure concept. Inspired by those findings, we embarked on the design and chemical synthesis of three distinct novel spirocyclic scaffolds that qualify for downstream library synthesis, thus exploring principally new chemical space with high potential for pharmaceutical
arylboronic acids to isatins. Asymmetric synthesis of 3‐aryl‐3‐hydroxy‐2‐oxindoles by 1,2‐addition of arylboronic acids to isatins was carried out in the presence of [RuCl2(PPh3)3]/(R,R)‐Me‐BIPAM and KF, resulting in an enantioselectivity as high as 90 % ee. It was found that the reaction with N‐protected isatins proceeds with high yields and good enantioselectivities. The best protective groups on the
Chameleon-Like Activating Nature of the Spirooxindole Group in Donor–Acceptor Cyclopropanes
作者:Andrey A. Akaev、Mikhail Ya. Melnikov、Ekaterina M. Budynina
DOI:10.1021/acs.orglett.9b04153
日期:2019.12.6
The concept of a chameleon activating group is considered in the context of donor-acceptor cyclopropane chemistry. When spiro-conjugated with cyclopropane, oxindole can act as an acceptor or a donor depending on the electronic nature of vicinal substituents. This dichotomy is reflected in the alteration of chemoselectivity of spiro[oxindole-1,3'-cyclopropane] ringopening with nucleophiles.