A highly efficient strategy for the kinetic resolution of Michael adducts was realized using a chiral N‐heterocyclic carbene catalyst. The kinetic resolution provides a new convenient route to single diastereomers of cyclohexenes and Michael adducts in good yields with high enantiomeric excesses (up to 99 % ee with a selectivity factor of up to 458). This “two flies with one swat” concept allows the
One‐Pot Sequential Synthesis of Fused Isoquinolines via Intramolecular Cyclization/Annulation and their Photophysical Investigation
作者:Amitava Rakshit、Prasenjit Sau、Subhendu Ghosh、Bhisma K. Patel
DOI:10.1002/adsc.201900543
日期:2019.8.21
1‐a]isoquinoline‐3‐carbonitrile. This one‐pot process is associated with the formation of one C−C, two C−N, two C=C and a C=O bonds. The final synthesis is a four‐step process consisting of selective hydrolysis of a cyano group to an amide, dehydrative cyclization of the amide to a cyclic amide, aromatization of the cyclic amide (2‐oxo‐1,2,3,4‐tetrahydropyridine moiety) to a 2‐oxo‐1,2‐dihydropyridine and finally
作者:Lutz Greiner-Bechert、Thomas Sprang、Hans-Hartwig Otto
DOI:10.1007/s00706-004-0265-8
日期:2005.4
Heteroaryl substituted cyclopropyl ketones were prepared by reactions with Me 3SO+ I+, and by reaction with Lewis acids they were transformed into substituted dihydrobenzo[ b ]furanone or -thiophenone, or γ-hydroxy ketones. Cycloadditions with thiophene derivatives allowed the synthesis of substituted benzo[ b ]thiophene derivatives, but with poor yields. Structures and stereochemistry were established mainly
噻吩基和呋喃基丙烯酮与丙二酸酯,氰基乙酸酯和丙二腈反应,生成可环化为杂芳基取代的二氢吡喃,环己醇和哌啶酮的加成产物。杂芳基取代的环丙基酮是通过与 Me 3 SO + I +反应制备的 ,并且通过与 路易斯 酸反应,将 它们转化为取代的二氢苯并[ b ]呋喃酮或-噻吩酮或γ-羟基酮。与噻吩衍生物的环加成可以合成取代的苯并[ b ]噻吩衍生物,但收率很低。主要通过NMR光谱确定结构和立体化学。
A dynamic kinetic asymmetric transfer hydrogenation–cyclization tandem reaction: an easy access to chiral 3,4-dihydro-2H-pyran-carbonitriles
作者:Dongsong Zheng、Qiankun Zhao、Xiaoying Hu、Tanyu Cheng、Guohua Liu、Wei Wang
DOI:10.1039/c7cc02156a
日期:——
(mesitylene)RuCl(monosulfonated diamine) catalysed dynamickineticresolution (DKR)–asymmetric transfer hydrogenation (ATH) process is developed for highly enantio- (up to 99% ee) and diastereo- (up to 98:2 dr) selective reduction of challenging racemic α-aryl-γ-keto malononitriles. A spontaneous cyclization reaction of the hydrogenation products delivers a cascadeprocess for efficient synthesis of useful enantioenriched