823182-69-0Relevant articles and documents
Sulfur-controlled and rhodium-catalyzed formal (3 + 3) transannulation of thioacyl carbenes with alk-2-enals and mechanistic insights
Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
supporting information, p. 3173 - 3180 (2021/04/21)
A rhodium-catalyzed denitrogenative formal (3 + 3) transannulation of 1,2,3-thiadiazoles with alk-2-enals is achieved, producing 2,3-dihydrothiopyran-4-ones in moderate to excellent yields. An inverse KIE of 0.49 is obtained, suggesting the reversibility of the oxidative addition of thioacyl Rh(i) carbenes to alk-2-enals. The late-stage structural modifications of steroid compounds are realized. Moreover, our studies show that thioacyl carbenes have different reactivities to those of α-oxo and α-imino carbenes, and highlight the importance of heteroatoms in deciding the reactivities of heterovinyl carbenes.
C-H Activation-Based Traceless Synthesis via Electrophilic Removal of a Directing Group. Rhodium(III)-Catalyzed Entry into Indoles from N-Nitroso and α-Diazo-β-keto Compounds
Wang, Jie,Wang, Mingyang,Chen, Kehao,Zha, Shanke,Song, Chao,Zhu, Jin
supporting information, p. 1178 - 1181 (2016/03/15)
A distinct C-H activation-based traceless synthetic protocol via electrophilic removal of a directing group is reported, complementing the currently exclusively used nucleophilic strategy. Rh(III)-catalyzed, N-nitroso-directed C-H activation allows the development of a traceless, atom- and step-economic, cascade approach for the synthesis of indole skeletons, starting from readily available N-nitroso and α-diazo-β-keto compounds. Importantly, the cyclization/denitrosation reaction represents a hitherto unobserved reactivity pattern for the N-nitroso group.
Catalytic, Cascade Ring-Opening Benzannulations of 2,3-Dihydrofuran O,O- and N,O-Acetals
Aponte-Guzmán, Joel,Phun, Lien H.,Cavitt, Marchello A.,Taylor, J. Evans,Davy, Jack C.,France, Stefan
supporting information, p. 10405 - 10409 (2016/07/21)
An Al(OTf)3-catalyzed intramolecular cascade ring-opening benzannulation of 2,3-dihydrofuran O,O- and N,O-acetals is described. The cascade sequence involves the dihydrofuran ring-opening by acetal hydrolysis, an intramolecular Prins-type cyclization, and aromatization to generate an array of benzo-fused (hetero)aromatic systems in up to 95 % yield. This method represents the first example of dihydrofuran acetal usage in benzannulation reactions. The approach provides excellent regiocontrol based on the choice of alkenes used to form the requisite dihydrofuran acetals.
Nucleophilic fluorination of β-ketoester derivatives with HBF 4
Pasceri, Raffaele,Bartrum, Hannah E.,Hayes, Christopher J.,Moody, Christopher J.
supporting information, p. 12077 - 12079 (2013/01/16)
Treating readily available α-diazo-β-ketoesters with HBF 4 results in nucleophilic fluorination by the usually inert and stable tetrafluoroborate anion. The resulting α-fluoro-β-ketoesters are highly versatile synthetic intermediates, for example in the preparation of fluoro-heterocycles, as illustrated by the direct formation of fluoro-pyrimidines, -pyrazoles and -coumarins in a single step.
