Palladium-Catalyzed [5 + 2] Annulation of Vinylethylene Carbonates with Barbiturate-Derived Alkenes
摘要:
A palladium/XantPhos-catalyzed [5 + 2] annulation of VECs with electron-deficient alkenes having an isolated carbon-carbon double bond has been developed to afford spirobarbiturate-tetrahydrooxepines. This study provides an expedient assembly of biologically interesting spirobarbiturate-tetrahydrooxepines. The easy scalability and versatile transformability of the reaction products were also exhibited.
Catalytic, Enantioselective Alkylation of α-Imino Esters: The Synthesis of Nonnatural α-Amino Acid Derivatives
作者:Dana Ferraris、Brandon Young、Christopher Cox、Travis Dudding、William J. Drury、Lev Ryzhkov、Andrew E. Taggi、Thomas Lectka
DOI:10.1021/ja016838j
日期:2002.1.1
Methodology for the practical synthesis of nonnatural amino acids has been developed through the catalytic, asymmetric alkylation of α-imino esters and N,O-acetals by enol silanes, ketene acetals, alkenes, and allylsilanes using chiral transition metal-phosphine complexes as catalysts (1−5 mol %). The alkylation products, which are prepared with high enantioselectivity (up to 99% ee) and diastereoselectivity
[reaction: see text] Catalytic, enantioselective Mannich-type reactions of alpha-imino estersbearing readily removable substituents on nitrogen are described. Several N-carbamate-protected alpha-imino esters, which are readily prepared from 2-bromoglycine esters using a polymer-supported amine, reacted with silicon enolates to afford the desired adducts in high yields with high enantioselectivity
enolates with N-acyl-α-iminophosphonates leading to optically active α-amino phophonates. A copper (II)−diamine complex was shown to be effective in this reaction, and high levels of yield and selectivity were achieved. It is noteworthy that this reaction opens a way to various biologically important, optically active α-aminophosphonate derivatives.
作者:Liang, Tongwei、Yuan, Qingjia、Xu, Li、Liu, Jian-Quan、Kärkäs, Markus D.、Wang, Xiang-Shan
DOI:10.1021/acs.joc.4c00310
日期:——
for the intermolecular radical umpolung cross-coupling protocol of silylenolethers with activated methylene compounds is disclosed. The protocol exhibits excellent functional group tolerance, enabling the expedient preparation of a variety of tricarbonyl compounds. Preliminary mechanistic investigations suggest that the reaction proceeds through a process involving free radicals in which silver oxide
A topliss tree analysis of the HIV-protease inhibitory activity of 6-phenyl-4-hydroxy-pyran-2-ones
作者:Bruce A. Steinbaugh、Harriet W. Hamilton、J.V.N. Vara Prasad、Kimberly S. Para、Peter J. Tummino、Donna Ferguson、Elizabeth A. Lunney、C. John Blankley
DOI:10.1016/0960-894x(96)00180-1
日期:1996.5
In a study of 4-hydroxy-pyran-2-ones as possible inhibitors of HIV protease, a series of compounds were synthesized following the Topliss operational scheme for substitution on a phenyl group at the 6 position of the pyrone. In addition, a number of compounds with polar substituents were made. (C) 1996 Elsevier Science Ltd