51174-44-8Relevant academic research and scientific papers
Pd(II)-Catalyzed [4 + 2] Heterocyclization Sequence for Polyheterocycle Generation
Glaisyer, Elizabeth L.,Watt, Michael S.,Booker-Milburn, Kevin I.
supporting information, p. 5877 - 5880 (2018/09/25)
A new Pd(II)-catalyzed cascade sequence for the formation of polyheterocycles, from simple starting materials, is reported. The sequence is applicable to both indole and pyrrole substrates, and a range of substituents are tolerated. The reaction is thought to proceed by a Pd(II)-catalyzed C-H activated Heck reaction followed by a second Pd(II)-catalyzed aza-Wacker reaction with two Cu(II)-mediated Pd(0) turnovers per sequence. The sequence can be considered a formal [4 + 2] heterocyclization.
COMPOUNDS THAT INHIBIT MCL-1 PROTEIN
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Page/Page column 1196; 1197, (2017/09/15)
Provided herein are myeloid cell leukemia 1 protein (Mcl-1) inhibitors, methods of their preparation, related pharmaceutical compositions, and methods of using the same. For example, provided herein are compounds of Formula I, and pharmaceutically acceptable salts thereof and pharmaceutical compositions containing the compounds. The compounds and compositions provided herein may be used, for example, in the treatment of diseases or conditions, such as cancer.
Br?nsted Acid Catalysis in Visible-Light-Induced [2+2] Photocycloaddition Reactions of Enone Dithianes
Brenninger, Christoph,P?thig, Alexander,Bach, Thorsten
supporting information, p. 4337 - 4341 (2017/04/04)
1,3-Dithiane-protected enones (enone dithianes) were found to undergo an intramolecular [2+2] photocycloaddition under visible-light irradiation (λ=405 nm) in the presence of a Br?nsted acid (7.5–10 mol %). Key to the success of the reaction is presumably the formation of colored thionium ions, which are intermediates of the catalytic cycle. Cyclobutanes were thus obtained in very good yields (78–90 %). It is also shown that the dithiane moiety can be reductively or oxidatively removed without affecting the photochemically constructed ring skeleton.
Molecular basis for the enantio-and diastereoselectivity of burkholderia cepacia lipase toward γ-butyrolactone primary alcohols
Eum, Heesung,Kazlauskas, Romas J.,Ha, Hyun-Joon
, p. 3585 - 3599 (2015/02/19)
Burkholderia cepacia lipase (BCL) shows high enantioselectivity toward chiral primary alcohols, but this enantioselectivity is often unpredictable, especially for substrates that contain an oxygen at the stereocenter. For example, BCL resolves bsubstituted-g-acetyloxymethyl-g-butyrolactones (acetates of a chiral primary alcohol) by hydrolysis of the acetate, but the enantioselectivity varies with the nature and orientation of the b-alkyl substituent. BCL favors the (R)-primary alcohol when the balkyl substituent is hydrogen (E=30) or trans methyl (E=38), but the (S)-primary alcohol when it is cis methyl (E=145). To rationalize this unusual selectivity, we used a combination of experiments to show the importance of polar interactions and modeling to reveal differences in orientations of the enantiomers. Removal of either the lactone carbonyl in the substrate or the polar side chains in the enzyme by using a related enzyme without these side chains decreased the enantioselectivity at least four-fold. Modeling revealed that the slow enantiomers do not bind by exchanging the location of two substituents relative to the fast enantiomer. Instead, three substituents remain in the same region, but the fourth substituent, hydrogen, inverts to a new location, like an umbrella in a strong wind. In this orientation the favored stereoisomers have similar shapes, thus accounting for the unusual stereoselectivity. The ratio of catalytically productive orientations for the fast vs. slow enantiomers in a molecular dynamic simulation correlated (R2=0.82) with the degree of enantioselectivity including the case where the enantioselectivity reversed. Weighting this ratio by the ratio of Hbonds in the polar interaction to account for different binding strengths improved the correlation with the measured enantioselectivity to R2=0.97. The modeling identifies key interactions responsible for high enantioselectivity in this class of substrates.
Molecular basis for the enantio- and diastereoselectivity of burkholderia cepacia lipase toward γ-Butyrolactone primary alcohols
Eum, Heesung,Kazlauskas, Romas J.,Ha, Hyun-Joon
, p. 3585 - 3599 (2015/02/19)
Burkholderia cepacia lipase (BCL) shows high enantioselectivity toward chiral primary alcohols, but this enantioselectivity is often unpredictable, especially for substrates that contain an oxygen at the stereocenter. For example, BCL resolves bsubstituted- g-acetyloxymethyl-g-butyrolactones (acetates of a chiral primary alcohol) by hydrolysis of the acetate, but the enantioselectivity varies with the nature and orientation of the b-alkyl substituent. BCL favors the (R)-primary alcohol when the balkyl substituent is hydrogen (E=30) or trans methyl (E=38), but the (S)-primary alcohol when it is cis methyl (E=145). To rationalize this unusual selectivity, we used a combination of experiments to show the importance of polar interactions and modeling to reveal differences in orientations of the enantiomers. Removal of either the lactone carbonyl in the substrate or the polar side chains in the enzyme by using a related enzyme without these side chains decreased the enantioselectivity at least four-fold. Modeling revealed that the slow enantiomers do not bind by exchanging the location of two substituents relative to the fast enantiomer. Instead, three substituents remain in the same region, but the fourth substituent, hydrogen, inverts to a new location, like an umbrella in a strong wind. In this orientation the favored stereoisomers have similar shapes, thus accounting for the unusual stereoselectivity. The ratio of catalytically productive orientations for the fast vs. slow enantiomers in a molecular dynamic simulation correlated (R2=0.82) with the degree of enantioselectivity including the case where the enantioselectivity reversed. Weighting this ratio by the ratio of Hbonds in the polar interaction to account for different binding strengths improved the correlation with the measured enantioselectivity to R2=0.97. The modeling identifies key interactions responsible for high enantioselectivity in this class of substrates.
Hepatitis C Virus Inhibitors
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Page/Page column, (2013/06/26)
Hepatitis C virus inhibitors having the general formula (I) are disclosed. Compositions comprising the compounds and methods for using the compounds to inhibit HCV are also disclosed.
Remote control of regio- and diastereoselectivity in the hydroformylation of bishomoallylic alcohols with catalytic amounts of a reversibly bound directing group
Gruenanger, Christian U.,Breit, Bernhard
supporting information; experimental part, p. 967 - 970 (2010/05/02)
(Figure Presented) Remote and reversible! Phosphinites serve as reversibly bound directing groups for the remote control of the regio- and diastereoselective hydroformylation of bishomoallylic alcohols (see scheme; r.r: regioisomer ratio). The distance between the double bond and the functional hydroxy group to which the directing group is reversibly bound is the longest ever reported.
NHC-Catalyzed intramolecular redox amidation for the synthesis of functionalized lactams
Thai, Karen,Wang, Li,Dudding, Travis,Bilodeau, Francois,Gravel, Michel
supporting information; experimental part, p. 5708 - 5711 (2011/03/19)
A very efficient NHC-catalyzed lactamization reaction is reported. For most cases, the ring expansion reaction proceeds to cleanly furnish five- and six-membered N-Ts and N-Bn lactams, without the need for further purification. Evidence is presented suggesting a dual role for the stoichiometric base: (1) deprotonation of the triazolium precatalyst and (2) activation of the nitrogen leaving group through hydrogen bonding.
Acyloxyetherifications mediated by lead tetracarboxylates
Cottrell, Ian F.,Moloney, Mark G.,Smithies, Kirsty
supporting information; experimental part, p. 1097 - 1099 (2009/05/27)
Lead(IV) tetracarboxylates are capable of reacting with unsaturated alcohols to give the products of cyclic acyloxyetherification, usually as a mixture of tetrahydro-2H-pyranyl and tetrahydrofuranyl compounds.
A ring-closing metathesis approach to cyclic α,β-dehydroamino acids
Hekking, Koen F. W.,Waalboer, Dennis C. J.,Moelands, Marcel A. H.,Van Delft, Floris L.,Rutjes, Floris P. J. T.
supporting information; experimental part, p. 95 - 106 (2009/04/10)
A comprehensive study on the synthesis and ring-closing metathesis (RCM) of α,β-dehydroamino acids is described. This sequence has led to the formation of a range of biologically relevant functionalized nitrogen heterocycles. The incorporation of chiral b
