Efficient base catalyzed alkylation reactions with aziridine electrophiles
作者:Thomas A. Moss、Aurelie Alba、David Hepworth、Darren J. Dixon
DOI:10.1039/b802447b
日期:——
N-Mesitylene sulfonyl and N-tosyl aziridines have been identified as effective electrophiles in alkylation reactions of carbon acids catalyzed by the organic phosphorine base BEMP; yields of up to 99% for a range of pro-nucleophiles under mild reaction conditions are reported.
Enantio- and Diastereoselective Catalytic Alkylation Reactions with Aziridines
作者:Thomas A. Moss、David R. Fenwick、Darren J. Dixon
DOI:10.1021/ja8036965
日期:2008.8.1
The first asymmetric phase transfer catalyzed alkylation reaction of a range of carbon acids with N-sulfonyl aziridines is reported. When 10 mol % of a cinchona derived quaternary ammonium salt was employed as the catalyst under mildly basic conditions, N-o-(trifluoromethane)benzenesulfonyl aziridine was efficiently ring-opened to afford the amino ethylene products in consistently high yields and high
Homo- and heteropolynuclear Ni2+ and Cu2+ complexes of polytopic ligands, consisting of a tren unit substituted with three 12-membered tetraazamacrocycles
作者:Liselotte Siegfried、C. Niamh McMahon、Jan Baumeister、Markus Neuburger、Thomas A. Kaden、Sreekanth Anandaram、Cornelia G. Palivan
DOI:10.1039/b709422a
日期:——
Cu(2+) and Ni(2+) complexes with L3 (1-(N-methyl-2-aminoethyl-1,4,7,10-tetraazacyclododecane)) were also investigated. The crystal structures of [CuL3H(H(2)O)](ClO(4))(3) and [NiL3Cl](ClO(4)) were solved and show that the side chain in its protonated form is not involved in coordination, whereas deprotonated it binds to the metalion. The thermodynamically stable 3:1 complexes of L1 or L2 have a metal
Development of Macrocyclic Mn(II)−Bispyridine Complexes as pH‐Responsive Magnetic Resonance Imaging Contrast Agents
作者:Xiaojuan Shen、Yan Pan、Guohai Liang
DOI:10.1002/ejic.202200786
日期:——
efficient response to pH stimuli, and easy modulation characteristics were synthetized in this study. These complexes are considered ideal candidates for use as acidic microenvironment-specific MRI contrastagents.
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