One-Pot Double [3 + 2] Cycloadditions for Diastereoselective Synthesis of Pyrrolidine-Based Polycyclic Systems
作者:Xiaofeng Zhang、Weiqi Qiu、Xiaoming Ma、Jason Evans、Manpreet Kaur、Jerry P. Jasinski、Wei Zhang
DOI:10.1021/acs.joc.8b02046
日期:2018.11.2
Sequential inter- and intramolecular [3 + 2] cycloadditions of azomethine ylides are developed for the one-pot and diastereoselectivesynthesis of highly condensed heterocyclic systems containing pyrrolidine and up to seven stereocenters. It has high synthetic efficiency and operational simplicity, and only water was generated as a byproduct.
Highly diastereoselective synthesis of polycyclic amines via redox neutral C–H functionalization
作者:Chottanahalli S. Pavan Kumar、Kachigere B. Harsha、Nagarakere C. Sandhya、Ajjalli B. Ramesha、Kempegowda Mantelingu、Kanchugarakoppal S. Rangappa
DOI:10.1039/c5nj01706h
日期:——
Synthesis of polycyclic amines was achieved by benzoic acid catalysed reaction of 1-aryl THIQs and 1-aryl trypolines with o-allyl salicylaldehydes through the in situ generated azomethine ylide intermediates that undergo intramolecular [3+2]-cycloadditions with four new stereogenic centers in excellent diastereoselectivities under simple and mild conditions.
N‐Heterocyclic Carbene Acyl Anion Organocatalysis by Ball‐Milling
作者:William I. Nicholson、Alex C. Seastram、Saqib A. Iqbal、Benjamin G. Reed‐Berendt、Louis C. Morrill、Duncan L. Browne
DOI:10.1002/cssc.201902346
日期:2020.1.9
The ability to conduct N-heterocyclic carbene-catalysed acylanion chemistry under ball-milling conditions is reported for the first time. This process has been exemplified through applications to intermolecular-benzoin, intramolecular-benzoin, intermolecular-Stetter and intramolecular-Stetter reactions including asymmetric examples and demonstrates that this mode of mechanistically complex organocatalytic
Fluorous diastereomeric mixture synthesis (FDMS) of hydantoin-fused hexahydrochromeno[4,3-b]pyrroles
作者:Yimin Lu、Steven J. Geib、Krishnan Damodaran、Bin Sui、Zijuan Zhang、Dennis P. Curran、Wei Zhang
DOI:10.1039/c0cc01967d
日期:——
Fluorous diastereomeric mixture synthesis (FDMS) is introduced and demonstrated in the synthesis of six diastereomers of hydantoin-fused hexahydrochromeno[4,3-b]pyrroles.
The intermolecular or intramolecular asymmetric benzoin reaction was catalyzed by a small amount of N-heterocyclic carbene (NHC) (0.2–1 mol %) under solvent-free conditions. The solvent-free intramolecular asymmetric Stetterreaction also proceeded efficiently with NHC (0.2–1 mol %). In some cases, even solid-to-solid or solid-to-liquid conversions took place with low catalyst loading (0.2–1 mol %)