InBr3-catalyzed reduction of ketones with a hydrosilane: deoxygenation of aromatic ketones and selective synthesis of secondary alcohols and symmetrical ethers from aliphatic ketones
An InBr3–Et3SiH reducing system was developed to selectively convert aliphatic ketones to a variety of secondary alcohols in moderate to good yields. An initial mixing of InBr3 and PhSiH3 was followed by the addition of aliphatic ketones and a solvent to afford the symmetrical ether derivatives.
Synthesis, Characterization, and Conformational Analysis of DNA Adducts from Methylated Anilines Present in Tobacco Smoke
作者:M. Matilde Marques、Luísa L. G. Mourato、M. Amélia Santos、Frederick A. Beland
DOI:10.1021/tx950044z
日期:1996.1.1
to the arylaminenitrogen had a higher percentage of syn conformers. This observation was supported by theoretical simulation studies that indicated substantial percentages of low energy syn conformers, increasing with the substitution pattern in the order para < meta < ortho < ortho,para < ortho,meta. The results demonstrate that, although single-ring arylamines are considered weak carcinogens, their
烟草烟雾中存在的一系列芳香胺(2-,3-和4-甲基苯胺,2,3-和2,4-二甲基苯胺)与DNA结合的能力已通过N-(酰氧基)芳基胺的反应进行了研究带有dG,dG核苷酸和DNA。通过光谱法和HPLC法将与dG和核苷酸反应的主要产物表征为N-(脱氧鸟苷-8-基)芳基胺。修饰DNA的HPLC和光谱分析表明相同的加合物。1 H和13 C NMR光谱的分析表明,含有在芳基胺氮上邻位的甲基取代基的加合物具有较高百分比的顺式构象异构体。这一观察结果得到理论模拟研究的支持,该研究表明低能同构异构体的百分比很高,并且随着取代模式的增加,其对位
A Ruthenium Complex-Catalyzed Cyclotrimerization of Halodiynes with Nitriles. Synthesis of 2- and 3-Halopyridines
undergo [2+2+2] cyclotrimerization with nitriles in the presence of a catalytic amount of the ruthenium complex Cp*RuCl(cod) (10 mol%) to afford the corresponding halopyridines under ambient conditions in good isolated yields (up to 90%). The halopyridines are formed as two separable regioisomers. This is the first example of a direct synthesis of halopyridines from haloalkynes and nitriles.
AbstractTwo methods for the synthesis of newaxiallychiral bipyridine N,N′-dioxides based on catalytic [2+2+2] cyclotrimerization of diynes with nitriles were developed. The N,N′-dioxides were used as catalysts in enantioselectiveallylation of benzaldehyde with allyltrichlorosilane and aldol reaction of trichlorosilyl ketene acetal of methyl acetate with acetophenone. Graphical abstract
Additions of structurally diverse α-ketonitriles to aromatic and aliphatic prochiral aldehydes yielding highly enantioenriched acylated cyanohydrins were achieved using a combination of a titanium salen dimer and an achiral or chiral Lewis base. In most cases high yields and high enantioselectivities were observed. The ee was moderate in the initial part of the reaction but increased over time. This