Cyanoborohydrides are efficient reagents in the reductive addition reactions of alkyl iodides and electron-deficient olefins. In contrast to using tinreagents, the reaction took place chemoselectively at the carbon–iodine bond but not at the carbon–bromine or carbon–chlorine bond. The reaction system was successfully applied to three-component reactions, including radical carbonylation. The rate constant
氰基硼氢化物是烷基碘化物和缺电子烯烃的还原加成反应中的有效试剂。与使用锡试剂相反,该反应在碳碘键上发生化学选择,而在碳溴或碳氯键上没有发生。该反应体系已成功应用于三组分反应,包括自由基羰基化。通过动力学竞争法,在25°C下从氰基硼氢化四丁基铵中伯烷基脱氢的速率常数估计为<1×10 4 M –1 s –1。该值比氢化三丁基锡的值小3个数量级。
AZEPANE DERIVATIVES AND METHODS OF TREATING HEPATITIS B INFECTIONS
申请人:Novira Therapeutics, Inc.
公开号:US20150197493A1
公开(公告)日:2015-07-16
Provided herein are compounds useful for the treatment of HBV infection in a subject in need thereof, pharmaceutical compositions thereof, and methods of inhibiting, suppressing, or preventing HBV infection in the subject.
Cross-coupling of alkyl halides with aryl or alkyl Grignards catalyzed by dinuclear Ni(ii) complexes containing functionalized tripodal amine-pyrazolyl ligands
作者:Fei Xue、Jin Zhao、T. S. Andy Hor
DOI:10.1039/c3dt32111h
日期:——
Structurally distinctive dinuclear Ni(II) complexes with furan or thiophene tethered amine-pyrazolyl tripodal hybrid ligands have been synthesized and crystallographically characterized. All complexes are catalytically active towards cross-coupling of aryl/alkyl Grignard reagents with β-H containing alkyl halides at room temperature in the presence of N,N,N′,N′-tetramethylethylenediamine (TMEDA). The catalytic efficacy of the complexes is dependent on the tether substituent at the central amine. Two species, Ni(II) TMEDA and Mg(II) TMEDA complexes, have been isolated from the catalytic reaction mixtures under different conditions. Some ligand-stabilized Ni(II) and Mg(II) bimetallic species have also been identified in the ESI-MS spectra.
CuI-catalyzed coupling reaction of R(alkyl)-X with Ar(aryl)MgBr at rt was completed within 2 h. Effective leaving groups X in R-X were Br, I, OTs, but not Cl. Grignard reagents ArMgBr with both standard and bulky Ar such as 2-MeC6H4, 2-MeOC6H4, and 2,6-(Me)2C6H3 afforded the desired products in good yields. Ester and cyano groups in R-X were tolerated. Coupling reaction with R(alkyl)-MgBr proceeded as
在LiCl的存在下,在室温下2小时内完成CuI催化的R(烷基)-X与Ar(芳基)MgBr的偶联反应。RX中有效的离去基团X是Br,I,OT,但不是Cl。带有标准Ar和大块Ar的格氏试剂ArMgBr(例如2-MeC 6 H 4,2 -MeOC 6 H 4和2,6-(Me)2 C 6 H 3)以良好的收率提供了所需的产物。RX中的酯基和氰基基团是可容忍的。与R(烷基)-MgBr的偶联反应也进行。
Iron-Catalyzed Cross-Coupling of Alkyl Sulfonates with Arylzinc Reagents
Iron-catalyzedcross-coupling reactions of primary and secondary alkyl sulfonates with arylzinc reagents proceed smoothly in the presence of excess TMEDA and a concomitant magnesium salt. The arylzinc reagents are prepared from the corresponding aryllithium or magnesium reagents with ZnI2. The in situ formation of alkyl iodides and consecutive rapid cross-coupling avoids discrete preparation of the