Stereodefined Access to Lactams via Olefin Difunctionalization: Iridium Nitrenoids as a Motif of LUMO-Controlled Dipoles
摘要:
Reported herein is a general platform of a stereodefined access to gamma-lactams via Cp*Ir-catalyzed olefin difunctionalization, where in situ generated Ir-nitrenoid is utilized as a key motif of 1,3-dipoles to enable amido transfer in a syn-selective manner. Computational studies suggested that the stereodefined process can be attributed to the proposed working mode of concerted [3 + 2] cyclization. Frontier molecular orbital (FMO) analysis implied that a low-lying lowest unoccupied molecular orbital (LUMO) of the Ir-imido fragment engages in the olefin interaction. Mechanistic understanding on the nitrene transfer process led us to develop mild catalytic protocols of stereoselective difunctionalization of alkenyl dioxazolones to furnish alpha-(haloalkyl)- or (oxyalkyl)lactam products which are of high synthetic and medicinal utility. Product stereochemistry (threo and erythro) was found to be designated by the olefin geometry (E/Z) of substrates.
Chirale Diphosphinoterpene und deren Übergangsmetallkomplexe
申请人:LANXESS Deutschland GmbH
公开号:EP1595886A1
公开(公告)日:2005-11-16
Die vorliegende Erfindung betrifft chirale Diphosphinoterpene und deren Übergangsmetallkomplexe, ein Verfahren zur Herstellung chiraler Diphosphinoterpene bzw. deren Oxide und Übergangsmetallkomplexe enthaltend die chiralen Diphosphinoterpene. In einem weiteren Aspekt betrifft die Erfindung die Verwendung der chiralen Diphosphinoterpene bzw. deren Übergangsmetallkomplexe in asymmetrischen Synthesen.
Tethered Aminohydroxylation (TA) Reaction of Amides
作者:Timothy J. Donohoe、Cedric K. A. Callens、Amber L. Thompson
DOI:10.1021/ol900631y
日期:2009.6.4
The first examples of amide-tethered aminohydroxylationreactions, catalyzed by osmium, showing that the use of N−O-based reoxidants are essential for success, are reported. The system that is described is compatible with a variety of different alkene substitution patterns and ring sizes and works with low loadings in both cyclic and acyclic systems. The levels of diastereoselectivity that were observed
Four compounds with lactonemoiety were synthesized from chalcone 1 in three- or four-step synthesis. γ-Bromo-δ-lactone 5 was the only product of bromolactonization of acid 4 whereas bromolactonization of ester 3, apart from lactone 5 also afforded its isomer 6 and two diastereoisomeric δ-hydroxy-γ-lactones 7 and 8. Lactone 8 was also obtained in 88% yield as a product of simultaneous dehalogenation
Olefination of Aromatic Carbonyls via Site‐Specific Activation of Cycloalkanone Ketals**
作者:Tuong Anh To、Thanh Vinh Nguyen
DOI:10.1002/anie.202317003
日期:2024.1.2
A simple substrate design allows site-specific activation of cyclic ketones for olefination reaction of aromatic carbonyl compounds.
简单的底物设计允许环酮的位点特异性活化,用于芳香族羰基化合物的烯化反应。
Chirale Diphosphorverbindungen und deren Übergangsmetallkomplexe
申请人:LANXESS Deutschland GmbH
公开号:EP1595885A2
公开(公告)日:2005-11-16
Die vorliegende Erfindung betrifft chirale Diphosphorverbindungen und deren Übergangsmetallkomplexe, ein Verfahren zur Herstellung chiraler Diphosphorverbindungen bzw. deren Oxide und Übergangsmetallkomplexe enthaltend die chiralen Diphosphorverbindungen. In einem weiteren Aspekt betrifft die Erfindung die Verwendung der chiralen Diphosphorverbindungen bzw. deren Übergangsmetallkomplexe in asymmetrischen Synthesen.