General Approach to Nitrogen-Bridged Bicyclic Frameworks by Rh-Catalyzed Formal Carbenoid Insertion into an Amide C–N Bond
摘要:
Various nitrogen-bridged bicyclic skeletons are found in bioactive natural products and pharmaceuticals. The development of a new reaction to construct these molecular frameworks has attracted considerable attention in synthetic organic chemistry. We developed a novel synthetic method for obtaining a wide variety of nitrogen-bridged bicyclic compounds with a catalytic process, Rh-catalyzed formal carbenoid insertion into an amide C-N bond. Using 0.1-0.4 mol % Rh-2((NHCOBu)-Bu-t)(4) catalyst, various azabicydo[X.Y.Z]alkane derivatives were obtained in good to excellent yield, successfully demonstrating the broad substrate scope of the developed process. Experimental and computational studies to elucidate the reaction mechanism revealed that the formal insertion reaction of a carbenoid into an amide C-N bond proceeded via the formation of Rh-associated N-ylides, followed by an acyl group-selective Stevens [1,2]-shift through a concerted addition/elimination process on the sp(2)-hybridized carbon.
N-Cyanoimides: reactivity studies with amine nucleophiles
摘要:
N-Cyanoimides are useful precursors to N-alkyl or N-aryl imides. Treatment of aromatic N-cyanoimides such as N-cyanophthalimide (1) with primary amines provides N-substituted imides directly, while aliphatic N-cyanoimides afford diamide intermediates which can be converted to N-substituted imides upon heating.
Solvent-mediated One-pot Synthesis of Cyclic<i>N</i>-Substituted Imides
作者:Sambhaji V. Patil、Keshao A. Mahale、Kirankumar S. Gosavi、Ganesh B. Deshmukh、Nilesh S. Patil
DOI:10.1080/00304948.2013.798569
日期:2013.7.4
synthesized by elaboration of N-aryl maleimides.16–19 Evaluation of the available methods for the synthesis of N-substituted cyclic imides indicates that generally the amines are first reacted with the desired cyclic anhydride and the resulting amic acids are then cyclized to the corresponding imides using reagents such as Ac2O/NaOAc, Et3N/Ac2O, dimethyl sulfate/Na2CO3/tetrabutylammonium bromide,27 cyanuric
Catalytic Asymmetric Alkylation Reactions for the Construction of Protected Ethylene-Amino and Propylene-Amino Motifs Attached to Quaternary Stereocentres
作者:Thomas A. Moss、David M. Barber、Andrew F. Kyle、Darren J. Dixon
DOI:10.1002/chem.201203825
日期:2013.2.25
An efficient catalytic and stereoselective method for the direct construction of protected ethylene‐amino and propylene‐amino scaffolds attached to quaternary stereocentres is reported. Preliminary investigations revealed a mild base catalysed nucleophilic ring opening of N‐sulfonyl aziridines using the commercially available phosphazene base 2‐tert‐butylimino‐2‐diethylamino‐1,3‐dimethyl‐perhydro‐1
A synthesis of succinimides and glutarimides from cyclic anhydrides
作者:Tadashi Kometani、Tony Fitz、David S. Watt
DOI:10.1016/s0040-4039(00)84137-4
日期:1986.1
The transformation of cyclicanhydrides to their corresponding imides involves a mild three-step sequence: (1) reaction with a primary amine, (2) conversion of the intermediate monoamide to an N-hydroxysuccinimidyl ester using N,N′-disuccinimidyl oxalate (DSO), and (3) cyclization by heating the NHS ester in trichloroethylene in the presence of 4-(dimethylamino)pyridine.
A nanocomposite comprises a nanostructure, and a copolymer adsorbed to the nanostructure and containing at least one ionic monomer unit and a different monomer unit from the ionic monomer unit; the ionic monomer unit selected from the group consisting of a zwitterionic monomer unit and a cationic monomer unit which are represented by the following formula (1):
(in the formula (1), R
1
, R
2
, and R
3
each independently represent any one of a hydrogen atom and a monovalent organic group having 1 to 20 carbon atoms, Y
1
represents any one of a carbonyl group and an arylene group, Y
2
represents any one of —O— and —NH—, n is 0 or 1, R
4
represents a divalent organic group having 1 to 20 carbon atoms, and X represents any one of a zwitterionic group and a cationic group).
Unsaturated lactams with endo- or exocyclic C-C double bonds constitute a set of reactive inputs that serve as the electron-rich olefin component in Povarov reactions. These substrates afford the multicomponent adducts in convenient yields and offer a wide range of structural diversity. Postcondensation transformations allow direct access to a variety of lactam-fused and amide-substituted quinoline derivatives.