113273-67-9Relevant academic research and scientific papers
Stereoselective synthesis of cyclobutanes by contraction of pyrrolidines
Hui, Chunngai,Brieger, Lukas,Strohmann, Carsten,Antonchick, Andrey P.
, p. 18864 - 18870 (2021/11/23)
Here we report a contractive synthesis of multisubstituted cyclobutanes containing multiple stereocenters from readily accessible pyrrolidines using iodonitrene chemistry. Mediated by a nitrogen extrusion process, the stereospecific synthesis of cyclobutanes involves a radical pathway. Unprecedented unsymmetrical spirocyclobutanes were prepared successfully, and a concise, formal synthesis of the cytotoxic natural product piperarborenine B is reported.
A Facile Cu(I)/TF-BiphamPhos-catalyzed asymmetric approach to unnatural α-amino acid derivatives containing gem-bisphosphonates
Xue, Zhi-Yong,Li, Qing-Hua,Tao, Hai-Yan,Wang, Chun-Jiang
supporting information; experimental part, p. 11757 - 11765 (2011/09/16)
A novel catalytic asymmetric Michael addition of azomethine ylide with β-substituted alkylidene bisphosphates was realized in the presence of a chiral copper(I)/TF-BiphamPhos complex. The present system provides a unique and facile access to enantioenriched unnatural α-amino acid derivatives containing gem-bisphosphonates (gem-BPs) in high yields with excellent diastereoselectivities and enantioselectivities. Subsequent transformations lead to the expedient preparation of biologically active unnatural α-amino acid derivatives containing BPs and bisphosphonic acids without loss of diastereo- and enantiomeric excess.
Lithium Bromide/Triethylamine Induced Cycloaddition of N-Alkylidene 2-Amino Esters and Amides to Electron-Deficient Olefins with High Regio- and Stereoselectivity
Tsuge, Otohiko,Kanemasa, Shuji,Yoshioka, Manabu
, p. 1384 - 1391 (2007/10/02)
The imines of 2-amino esters and amides derived from glycine, alanine, and valine are deprotonated by the action of a lithium halide and triethylamine (or DBU).The resulting anionic intermediates undergo highly regio- and stereoselective cycloadditions with a variety of olefins activated by carbonyl-type substituents to produce stereochemically defined derivatives of proline esters or amides.The scope and limitations of this novel cycloaddition are discussed.
