<i>S</i><sub>N</sub>2 Reactions in Dipolar Aprotic Solvents. III. Chlorine Isotopic Exchange Reactions of Cinnamyl Chlorides and 3-Aryl-2-propynyl Chlorides. Effect of the Unsaturated Group Adjacent to the Reaction Center
作者:Jun-ichi Hayami、Nobuo Tanaka、Aritsune Kaji
DOI:10.1246/bcsj.46.954
日期:1973.3
Chlorine isotopic exchangereactions of substituted cinnamyl chlorides and 3-aryl-2-propynyl chlorides with tetraethylammonium chloride-36Cl were studied in acetonitrile. In both cases, the electron-donating groups accelerated the reaction. An acceptable linear Hammett relationship was found for the propynyl chlorides. Cinnamyl chlorides gave a linear relationship for the m-substituted compounds superposed
在乙腈中研究了取代的肉桂酰氯和 3-芳基-2-丙炔氯与四乙基氯化铵-36Cl 的氯同位素交换反应。在这两种情况下,给电子基团都加速了反应。发现丙炔氯具有可接受的线性哈米特关系。肉桂酰氯给出了由 p 取代化合物的凹 U 形关系叠加的 m 取代化合物的线性关系。在类似的同位素交换反应中,与 2-芳基乙基氯相比,两类化合物的速率提高了 102-3 倍。讨论了这些 SN2 反应的特征。
An efficient enantioselective alkylation of N‐unprotected 3‐substitutedoxindoles was realized by using a chiral N,N′‐dioxide/scandium(III) complex as the catalyst. A wide range of 3,3‐dialkyl substitutedoxindoles with quaternary stereocenters were obtained in high yields and ee values (up to 98% yield and 99% ee).
A gold-catalyzed cascade reaction of skippeddiynes (1,4-diynes) and pyrroles has been developed. This reaction proceeds by the consecutive regioselective hydroarylation of two alkynes with a pyrrole, followed by a 7-endo-dig cyclization to give 1,6-dihydrocyclohepta[b]pyrroles in good yields. The direct synthesis of cyclohepta[b]indoles using indole nucleophiles has also been reported.
已经开发了金催化的二炔(1,4-二炔)和吡咯的级联反应。该反应通过用吡咯连续进行两个炔烃的区域选择性加氢芳基化反应,然后进行7-内-挖-环化得到高收率的1,6-二氢环庚[ b ]吡咯。也已经报道了使用吲哚亲核试剂直接合成环庚[ b ]吲哚。
Synthesis of propargylic and allylic trifluoromethyl selenoethers by copper-mediated trifluoromethylselenolation of propargylic chlorides and allylic bromides
The copper-mediated trifluoromethylselenolation of propargylic chlorides and allylic bromides is described. This approach provides a wide range of propargylic and allylic trifluoromethyl selenoethers in moderate to good yields. These results open the way to synthesis strategies for various trifluoromethylselenolated compounds.