通过靛红和 2-(邻羟基亚苄基)-1,3-茚满二酮的 Morita-Baylis-Hillman (MBH) 碳酸酯的碱促进环化反应,方便地合成了多种功能化的二氢苯并呋喃螺环-茚满二酮-羟吲哚支架。以DABCO或DMAP为基础促进剂,可以选择性合成两个非对映体二螺[茚-2,1'-环戊[ b ]苯并呋喃-2',3"'-二氢吲哚]。更重要的是,DABCO或DMAP选择性地促进靛红和2-(邻羟基亚苄基)-1,3-茚二酮的MBH甲酸酯的成环反应,产生螺[环丙[ c ]色烯-1,2'-茚]-1 ',3'-二酮或二螺[茚-2,1'-环戊[ b ]苯并呋喃-2',3"'-二氢吲哚]。此外,与靛红的 MBH 马来酰亚胺进行类似反应,得到二螺[茚-2,5'-苯并呋喃[2',3':1,5]环戊[1,2- c ]吡咯-4',3"'-二氢吲哚] 高产率和高非对映选择性。
A highly regio- and stereoselective [3 + 2] cycloadditionreaction for constructing novel 3,3′-cyclopentenyldispirooxindoles incorporating two adjacent quaternary spirostereocenters is reported. Under the mild conditions, the asymmetric annulation of isatin-derived MBH carbonates with 3-methyleneoxindoles involving a chiral tertiary amine catalyst provides the corresponding dispirooxindole frameworks
here is an unprecedented auto‐tandem cooperative catalysis (ATCC) for Morita–Baylis–Hillmancarbonates from isatins and allyliccarbonates using a simple Pd(PPh3)4 precursor. Dissociated phosphine generates phosphorusylides and the Pd leads to π‐allylpalladium complexes, and they undergo a γ‐regioselective allylic–allylic alkylation reaction. Importantly, a cascade intramolecular Heck‐type coupling proceeds
Tertiary Amine-Catalyzed Difluoromethylthiolation of Morita-Baylis-Hillman Carbonates of Isatins with Zard's Trifluoromethylthiolation Reagent
作者:Xing Fan、Haibin Yang、Min Shi
DOI:10.1002/adsc.201600954
日期:2017.1.4
tertiary amine‐catalyzed [3+2] annulation between Morita–Baylis–Hillman (MBH) carbonates derived from isatins with thiocarbonyl fluoride (F2C=S) in situ generated from Zard's reagent proceeds smoothly under mild conditions, affording difluoromethylthiolated spirocyclic oxindoles in good to excellent yields. Moreover, the asymmetric variant could be realized with a modified Cinchonaalkaloid, giving the
在本文中,我们报道了一种新的叔胺催化的[3 + 2]环化反应,该反应是由Isards衍生的Morita–Baylis–Hillman(MBH)碳酸酯与异硫氰酸羰基氟化物(F 2 C = S)从Zard试剂原位生成的在温和的条件下,以良好或优异的收率得到二氟甲基硫醇化的螺环羟吲哚。此外,可以用修饰的金鸡纳生物碱实现不对称变体,从而以良好的对映体选择性以及良好的产率获得所需的环状加合物。
Pseudo‐Stereodivergent Synthesis of Enantioenriched Tetrasubstituted Alkenes by Cascade 1,3‐Oxo‐Allylation/Cope Rearrangement
of highly enantioenriched tetrasubstituted alkene architectures from isatin-based Morita-Baylis-Hillman carbonates and allylic derivatives, under the cooperative catalysis of a tertiary amine and a chiral iridium complex. The success of the switchable construction of the tetrasubstituted alkene motif relies on the diastereodivergent 1,3-oxo-allylation reaction between N-allylic ylides and chiral π-allyliridium