Enantioselective Total Synthesis of (−)‐Martinellic Acid
作者:Mukesh Pappoppula、Aaron Aponick
DOI:10.1002/anie.201507849
日期:2015.12.21
martinellic acid is described. The pyrroloquinoline alkaloid core is efficiently prepared from a quinoline, employing a method which relies on a newly developed Cu‐catalyzed enantioselective alkynylation using the chiral imidazole‐based biaryl P,Nligand StackPhos to establish the absolute stereochemistry. The remaining carbon atoms are then installed by means of a diastereoselective Pd‐catalyzed decarboxylative
作者:Mukesh Pappoppula、Flavio S. P. Cardoso、B. Owen Garrett、Aaron Aponick
DOI:10.1002/anie.201507848
日期:2015.12.7
A highly enantioselective copper‐catalyzed alkynylation of quinolinium salts is reported. The reaction employs StackPhos, a newly developed imidazole‐based chiral biaryl P,N ligand, and copper bromide to effect a three‐component reaction between a quinoline, a terminal alkyne, and ethyl chloroformate. Under the reaction conditions, the desired products are delivered in high yields with ee values of
Enantioselective Alkyne Conjugate Addition Enabled by Readily Tuned Atropisomeric <i>P</i>,<i>N</i>-Ligands
作者:Sourabh Mishra、Ji Liu、Aaron Aponick
DOI:10.1021/jacs.7b00363
日期:2017.3.8
structure, the 5-membered chiral biaryl heterocyclic scaffold represents a departure from 6-membered P,N-ligands that facilitates tuning and enables ligand evolution to address issues of selectivity and reactivity. In this vein, the Cu-catalyzedenantioselective conjugate alkynylation of Meldrum's acid acceptors is reported using Me-StackPhos. Enabled by this new ligand, the reaction tolerates a wide range
α‐Hydroxy‐Tetrazoles as Latent Ethynyl Moieties: A Mechanistic Investigation
作者:Pierre Quinodoz、Karen Wright、Bruno Drouillat、Mikhail E. Kletskii、Oleg N. Burov、Anton. V. Lisovin、François Couty
DOI:10.1002/ejoc.201800143
日期:2019.1.23
This article focuses on the dehydration of α‐hydroxy‐tetrazoles, leading to tetraazafulvenes and then to vinylic carbenes that rearrange into ethynyl moieties through the Fritsch–Buttenberg–Wiechell rearrangement. Each step of this sequence was scrutinized, either by examination of the substrate and/or dehydrating agent scope, or through AM1 calculations, in order to understand the limiting step of
The First Successful Base-Promoted Isomerization of Propargyl Amides to Chiral Ynamides. Applications in Ring-Closing Metathesis of Ene−Ynamides and Tandem RCM of Diene−Ynamides
作者:Jian Huang、Hui Xiong、Richard P. Hsung、C. Rameshkumar、Jason A. Mulder、Tyler P. Grebe
DOI:10.1021/ol020097p
日期:2002.7.1
[GRAPHICS]A highly useful sequence of reactions is described here. These reactions consist of the first successful base-induced isomerizations of propargyl amides to chiral ynamides, applications of these novel ynamides in ring-closure metathesis leading to chiral 2-amidodienes useful for Diels-Alder cycloadditions, and the first successful tandem RCM of diene-ynamides.