Ring Closure Reactions of Substituted 4-Pentenyl-1-oxy Radicals. The Stereoselective Synthesis of Functionalized Disubstituted Tetrahydrofurans
摘要:
N-(Alkyloxy)pyridine-2( VT)-thiones 3 and benzenesulfenic acid O-esters 5 have been synthesized from substituted 4-pentenols 1 or the derived tosylates. Compounds 3 and 5 are efficient sources of free alkoxy radicals 6 which undergo synthetically useful fast ring closure reactions 6 --> 8 [k(exo) = (2 +/- 1) x 10(8) s(-1) to (6 +/- 2) x 10(9) s(-1) (T = 30 +/- 0.2 degrees C)]. Tetrahydrofurfuryl radicals 8 can be trapped with, e.g., hydrogen or chlorine atom donors to afford either trans- or cis-disubstituted tetrahydrofurans 10 or 12 depending on the substitution pattern of the 4-pentenyloxy radical. Substituted tetrahydropyrans 11 or 13 are formed in the minor 6-endo-trig cyclization. According to the data of competition kinetics, the observed stereoselectivities in free alkoxy radical cyclizations arise from steric interactions between the substituents in the transition state of the ring closure reactions. Alkyl substituents cause small differences in the measured relative rate constants of B-exo cyclizations which are reminiscent of the data obtained from the rearrangements of alkyl-substituted 5-hexenyl radicals. Likewise, a stereochemical model for oxygen radical cyclization is proposed where the pentenyloxy chain adopts a six-membered, chairlike transition state with the alkyl substituents preferentially situated in the pseudoequatorial positions leading to 2,5-trans-, 2,4-cis-, and 2,3-trans-substituted tetrahydrofurfuryl radicals 8 as the major intermediates.
[EN] COMPOUNDS THAT INHIBIT MCL-1 PROTEIN<br/>[FR] COMPOSÉS INHIBANT LA PROTÉINE MCL-1
申请人:AMGEN INC
公开号:WO2017147410A1
公开(公告)日:2017-08-31
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.
[EN] AZABICYCLIC(THIO)AMIDES AS FUNGICIDAL COMPOUNDS<br/>[FR] (THIO)AMIDES AZABICYCLIQUES EN TANT QUE COMPOSÉS FONGICIDES
申请人:BAYER AG
公开号:WO2021233861A1
公开(公告)日:2021-11-25
The present invention relates to azabicyclic (thio)amide compounds and the uses thereof for controlling phytopathogenic microorganisms such as phytopathogenic fungi. It also relates to processes and intermediates for preparing these compounds
Intramolecular Pyridinium Oxide Cycloadditions: Systematic Study of Substitution, Diastereoselectivity, and Regioselectivity
作者:Yi Lu、Patrick N. Dey、Christopher M. Beaudry
DOI:10.1002/chem.202100115
日期:2021.2.24
Intramolecular pyridinium oxide cycloadditions form complex polycyclic nitrogenous architectures. The diastereoselectivity and regioselectivity of pyridinium oxide cycloadditions was systematically investigated for the first time using complex substrates. Predictably high levels of diastereoselectivity and regioselectivity are observed, which can be attributed to minimization of steric (syn‐pentane)
Pd(II)-Catalyzed [4 + 2] Heterocyclization Sequence for Polyheterocycle Generation
作者:Elizabeth L. Glaisyer、Michael S. Watt、Kevin I. Booker-Milburn
DOI:10.1021/acs.orglett.8b02543
日期:2018.9.21
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
[DE] VERFAHREN ZUR HERSTELLUNG VON 3-PHENYL(THIO)URACILEN UND - DITHIOURACILEN<br/>[EN] METHOD FOR THE PRODUCTION OF 3-PHENYL(THIO)URACILS AND DITHIOURACILS<br/>[FR] PROCEDE DE PRODUCTION DE 3-PHENYL(THIO)URACILES ET DE 3-PHENYL-DITHIO-URACILES
申请人:BASF AG
公开号:WO2006010474A1
公开(公告)日:2006-02-02
Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von 3-Phenyl(thio)uracilen und -dithiouracilen der Formel I, worin die Variablen die in der Beschreibung genannten Bedeutungen haben, dadurch gekennzeichnet, dass Carbamate der Formel II, wobei die Variablen X1, X3, Ar und A die zuvor genannten Bedeutungen haben und L1für eine nucleophil verdrängbare Abgangsgruppe steht, mit Enaminen der Formel III, wobei die Variablen X2, R1, R2 und R3 die zuvor genannten Bedeutungen haben und L2 für eine nucleophil verdrängbare Abgangsgruppe steht, umgesetzt werden, sowie Zwischenprodukte zu ihrer Herstellung.