Synthesis of diverse nitrogen fused polycyclic dihydroisoquinoline (DHIQ) derivatives via GBB-based cyclic iminium induced double-annulation cascade
作者:Sandip Gangadhar Balwe、Sandip S. Vagh、Yeon Tae Jeong
DOI:10.1016/j.tetlet.2020.152101
日期:2020.7
for the synthesis of novel dihydroindazolo[3′,2′:2,3]imidazo[5,1-a]isoquinolinamines has been achieved through the three-component Groebke–Blackburn–Bienayme reaction. The transformation is based on sequential cascade processes involving imine formation followed by an intramolecular nucleophilic substitution to generate a highly reactive cyclic iminium species, which would undergo a rapid [4 + 1] formal
通过合成实现了一种高效且独特的布朗斯台德酸介导的空前的环状亚胺诱导的双环级联反应(DAC)方案,用于合成新型二氢吲哚并[3',2':2,3]咪唑并[5,1- a ]异喹啉胺三组分Groebke–Blackburn–Bienayme反应。该转化基于顺序的级联过程,该过程涉及形成亚胺,然后进行分子内亲核取代,以生成高反应性的环亚胺,这些亚胺将以一锅方式快速[4 +1]正式的环加成步骤。通过采用容易获得的底物和简单的方法,该策略提供了新颖的骨架多样的复杂的氮稠合多环DHIQ衍生物,这将使该方法在有机合成中潜在有用。
Ytterbium-Catalyzed Intramolecular [3 + 2] Cycloaddition based on Furan Dearomatization to Construct Fused Triazoles
development of expeditious methods to synthesize these skeletons remains a challenging task. In this work, the catalyticcyclization of biomass-derived 2-furylcarbinols with an azide to form fused triazoles is described. This approach takes advantage of a single catalyst Yb(OTf)3 and operates via a furfuryl-cation-induced intramolecular [3 + 2] cycloaddition/furan ring-opening cascade.
A phosphane‐catalyzed [3+3] annulation of azomethineimines with ynones has been developed. Under mild reaction conditions, the reaction proceeds smoothly to afford tricyclic dinitrogen‐fused heterocyclic compounds in moderate to excellent yields with moderate to excellent stereoselectivies. Using a chiral phosphine as the catalyst, the reaction could work to give the cycloadduct in moderate yield
A Phosphine-Catalyzed Novel Asymmetric [3+2] Cycloaddition of C,N-Cyclic Azomethine Imines with δ-Substituted Allenoates
作者:De Wang、Yu Lei、Yin Wei、Min Shi
DOI:10.1002/chem.201405191
日期:2014.11.17
asymmetric [3+2] cycloadditions of C,N‐cyclic azomethine imines with δ‐substituted allenoates have been developed in the presence of (S)‐Me‐f‐KetalPhos, affording functionalized tetrahydroquinoline frameworks in good yields with high diastereo‐ and good enantioselectivities under mild condition. The substrate scope has been also examined. This is the first time that δ‐substituted allenoates have been
The first phosphine-catalyzed highly enantioselective [3 + 3] cycloaddition of Morita-Baylis-Hillman carbonates with C,N-cyclicazomethineimines is described. Using a spirocyclic chiral phosphine as the catalyst, a novel class of pharmaceutically interesting 4,6,7,11b-tetrahydro-1H-pyridazino[6,1-a]iso-quinoline derivatives were obtained in high yields with good to excellent diastereoselectivities