N-Heterocyclic Carbene-Catalyzed Formal [3 + 2] Annulation of α-Bromoenals with 3-Aminooxindoles: A Stereoselective Synthesis of Spirooxindole γ-Butyrolactams
作者:Delu Jiang、Shuding Dong、Weifang Tang、Tao Lu、Ding Du
DOI:10.1021/acs.joc.5b02188
日期:2015.11.20
A stereoselective synthetic approach to spirooxindole γ-butyrolactams is developed via N-heterocycliccarbene-catalyzedformal [3 + 2] annulation of α-bromoenals with 3-aminooxindoles. An enantioselective variant of this methodology is also investigated resulting in good substrate tolerance and high enantioselectivities.
N-Heterocyclic carbene-catalyzed [3 + 2] annulation of bromoenals with 3-aminooxindoles: highly enantioselective synthesis of spirocyclic oxindolo-γ-lactams
作者:Kun-Quan Chen、Yao Li、Chun-Lin Zhang、De-Qun Sun、Song Ye
DOI:10.1039/c5ob02466h
日期:——
The chiral N-heterocycliccarbene-catalyzed [3 + 2] annulation of α-bromoenals and 3-aminooxindoles was developed, giving the corresponding spirocyclic oxindolo-γ-lactams in good yields with high diastereoselectivities and enantioselectivities.
N-Heterocyclic Carbene-Catalyzed Chemoselective Cross-Aza-Benzoin Reaction of Enals with Isatin-Derived Ketimines: Access to Chiral Quaternary Aminooxindoles
作者:Jianfeng Xu、Chengli Mou、Tingshun Zhu、Bao-An Song、Yonggui Robin Chi
DOI:10.1021/ol501286e
日期:2014.6.20
A chemo- and enantioselective cross-aza-benzoin reaction between enals and isatin-derived ketimines is disclosed. The high chemoselectivity (of the acyl anion reaction over enal alpha- and beta-carbon reactions) is enabled by the electronic and steric properties of the N-heterocyclic carbene organocatalyst.
Highly Enantioselective Addition of Enals to Isatin-Derived Ketimines Catalyzed by N-Heterocyclic Carbenes: Synthesis of Spirocyclic γ-Lactams
作者:Hui Lv、Bhoopendra Tiwari、Junming Mo、Chong Xing、Yonggui Robin Chi
DOI:10.1021/ol302475g
日期:2012.11.2
An N-heterocycliccarbene (NHC)-catalyzed annulation reaction of isatin N-Boc ketimines and enals is developed for the synthesis of spirocyclic oxindole-γ-lactams bearing one quaternary chiral center in good yields and excellent stereoselectivities (up to >20:1 dr and 99% ee).