General Ir-Catalyzed N–H Insertions of Diazomalonates into Aliphatic and Aromatic Amines
作者:Zhuang Zhong、Céline Besnard、Jérôme Lacour
DOI:10.1021/acs.orglett.3c03929
日期:2024.2.9
reactivity of acceptor–acceptor diazo malonate reagents is reported using [Ir(cod)Cl]2 as catalyst. A large range of amines, primary and secondary, aliphatic and aromatic, is possible. Mild temperatures, perfect substrate/reactant stoichiometry, and good functional group compatibility render the process particularly attractive for the (late-stage) functionalization of amines.
Synthesis of Pyroglutamic Acid Derivatives via Double Michael Reactions of Alkynones
作者:Myriam Scansetti、Xiangping Hu、Benjamin P. McDermott、Hon Wai Lam
DOI:10.1021/ol070674f
日期:2007.5.1
In the presence of substoichiometric quantities of potassium tert-butoxide and an additional metal salt, amide-tethered diacids undergo double Michael reactions with alkynones to provide highly functionalized pyroglutamic acid derivatives. The metal salt was found to play an important role in improving the diastereoselectivities of the reactions.
Synthesis of pure methyl [(2S,3R,αR)-1-(3-bromo-4-methoxyphenyl)-3-(α-acetoxy)ethyl-4-oxoazetidin-2-carboxylate] and its enantiomer
Synthesis of key intermediates leading to 2-iso-oxacephems was carried out starting from L- and D-threonine. As predicted in our previous paper (Tetrahedron Lett. 1995, 36, 8303-8306) all diastereomers of 2-iso-oxacephems can be prepared from the appropriate enantiomers of the amino acid threonine. The absolute configuration of the 2,3- and alpha -carbon atoms in the beta -lactam structure was determined by X-ray crystallographic studies. (C) 2001 Elsevier Science Ltd. All rights reserved.
Stereocontrolled Synthesis of Methyl αR,2S,3R-3-(l-Acetoxyethyl)-1- (4-methoxyphenyl)-4-oxoazetidine-2-carboxylate
A stereocontrolled synthesis of the key intermediates for 2-iso-oxa- and 2-isocephems is described The absolute configuration of the title ester 8a is unambiguously determined by using X-ray analysis.
UREA DERIVATIVE OR PHARMACOLOGICALLY ACCEPTABLE SALT THEREOF