7 article(s) from Krasavin, Mikhail
Graphical Abstract
Figure 1: Examples of approved spirocyclic drugs.
Scheme 1: (a) Earlier reported Rh(II)-catalyzed spirocyclization of DAS with the formation of minor enol ethe...
Scheme 2: Initial attempt at Rh(II)-catalyzed O–H insertion/Claisen rearrangement.
Scheme 3: Rh2(esp)2-catalyzed O–H insertion reactions between various DAS 1 and phenols.
Scheme 4: Two-step, one-pot sequence of the Claisen rearrangement/intramolecular Michael-type spirocyclizatio...
Scheme 5: Tentative rationalization of the diastereoselectivity observed in all 5→7 transformations (shown fo...
Graphical Abstract
Figure 1: (a) Previously developed three-component approach to 1,5-disubstituted 1,2,3-triazoles; (b) double ...
Scheme 1: Results of a trial reaction between 1, o-azidobenzaldehyde (3a) and propargylamine.
Figure 2: Diversely bioactive compounds based on scaffolds A and B.
Scheme 2: Three-component reaction of 1, propargylamine and various o-azidobenzaldehydes.
Figure 3: Aromatic azido aldehydes 3j–l that failed to react with 1 and propargylamine.
Scheme 3: Variations of the amine component in the reactions with 1 and 3a.
Graphical Abstract
Figure 1: Diverse bioactive compounds based on the privileged 1,4-DHIQ scaffold.
Figure 2: Strategy investigated in this work.
Scheme 1: Preparation of 3(2H)-isoquinolones 11. aObtained as a 10:1 mixture of regioisomers; purified by cry...
Scheme 2: Preparation of 4-diazo-3(2H)-isoquinolones 10. aConfirmed by single-crystal X-ray crystallography (...
Scheme 3: TfOH-promoted arylation of diazo substrates 10. aStructure confirmed by single-crystal X-ray analys...
Scheme 4: Unexpected outcome of the TfOH-promoted arylation of 10a with N-formyl-N-methylaniline giving rise ...
Scheme 5: Plausible mechanism for the conversion of diazo substrates 10 to 4-aryl products 9 (shown for ArH =...
Graphical Abstract
Figure 1: Previously reported transformations of DAS (1) and their unusual dimerization investigated in this ...
Scheme 1: The result of Rh(II)-catalyzed decomposition of DAS 1r.
Scheme 2: Plausible mechanism for the formation of dimer 2a and indene 3a through the Rh(II)-catalyzed decomp...
Figure 2: Cytotoxicity of N-alkyl-substituted dibenzoazulenodipyrroles 2 against the A549 human lung adenocar...
Graphical Abstract
Figure 1: Previously reported uses of α-diazo-γ-butyrolactams 1 and 4.
Scheme 1: Generation and in situ RhII-catalyzed X–H insertion reactions of the diazo compounds 4a–c. Conditio...
Scheme 2: Formation of the enamine coupling products 8a and b.
Graphical Abstract
Figure 1: Examples of imidazole (1 and 2) and oxazole (3) syntheses from propargylamides previously reported ...
Figure 2: Substrate scope for the three-component synthesis of 5.
Figure 3: Plausible mechanism for the formation of 5.
Graphical Abstract
Figure 1: The Castagnoli–Cushman reaction (CCR).
Figure 2: Assembly of hexahydropyrrolo[1,2-b]isoquinoline core via the CCR and its occurrence in natural and ...
Figure 3: Indolenine substrates 9a–t investigated in this work. aPrepared for the first time (the rest are kn...
Figure 4: Anti- and syn-diastereomers of 10 and 10'.
Figure 5: Single-crystal X-ray structure of compound 10l.
Scheme 1: Formation of unwanted products 11 and 12 in lieu of the CCR with 9p–t.
Figure 6: Typical J(H11-H11a)-values and corresponding dihedral angles for syn- and anti-diastereomers of com...
Figure 7: The difference in the 13C NMR chemical shifts of the angular methyl group between syn- and anti-dia...
Figure 8: Criteria for stereochemistry assignment of anti-10o.
Scheme 2: Syn/anti isomerization of compound 10e.
Scheme 3: Alternative mechanistic pathways for the CCR.
Scheme 4: Formation and fate of Mannich adduct 13e.
Scheme 5: Mechanistic rationale for the 13e→ syn/anti-10e conversion.
Scheme 6: Decarboxylation of anti/syn-10h.