Aqueous in situ one-pot N-Boc-deprotection-cyclization of N alpha-Boc-dipeptidyl-tert-butyl and methyl esters under microwave irradiation afforded 2,5-diketopiperazines (DKPs) in excellent yields. This protocol is rapid, safe, environmentally friendly, and highly efficient, and showed that the tert-butoxy moiety is also an excellent leaving group for these cyclizations.
Hexafluoraceton als Schutzgruppen-und Aktivierungsreagenz in der Aminosäure-und Peptidchemie, 11. Mitt.: Ein neuer präparativ einfacher Zugang zu 2,5-Dioxopiperazinen und 2,5-Dioxomorpholinen
2,5-Dioxopiperazines with symmetrical as well as unsymmetrical substituent pattern can be obtained via 2,2-bis(trifluoromethyl)-1,3-oxazolidin-5-ones, and 2,5-dioxomorpholines via 2,2-bis-(trifluoromethyl)-1,3-dioxolan-4-ones, respectively.
Acid-promoted reactions in 1-hydroxy, 1-dimethylaminomethyl and 1-methylene-4-arylmethyl-2,4-dihydro-1H-pyrazino[2,1-b]quinazoline-3,6-diones
作者:Marı́a Luisa Heredia、Elena de la Cuesta、Carmen Avendaño
DOI:10.1016/s0040-4020(02)00619-1
日期:2002.7
The 1-dimethylaminomethyl or 1-methylene group of the title compounds was introduced through a Mannich or a tandem of Mannich–Hofmann reactions as the final step of a protocol that is shorter than other previously described for these precursors of N-acyliminium species. In these compounds, the acid-promoted intramolecular cyclizations of Pictet–Spengler-type were restricted to the N(2)-unsubstituted
通过曼尼希或串联曼尼希-霍夫曼反应引入标题化合物的1-二甲基氨基甲基或1-亚甲基,作为该方案的最后一步,该步骤比先前针对这些N-酰基species属物种的其他前者所描述的要短。在这些化合物中,Pictet-Spengler型的酸促进分子内环化作用仅限于N(2)-未取代的化合物,而它们的N(2)-甲基取代的类似物却提供了二聚化产物。通过将格氏试剂添加到2 H,4 H-吡嗪并[ 2,1 - b ]喹唑啉-1,3,6-三酮中可以得到1-羟基-1,2-二取代的化合物,该环化反应是有效的。
Linear and cyclic dipeptides with antimalarial activity
作者:Lemuel Pérez-Picaso、Horacio F. Olivo、Rocío Argotte-Ramos、María Rodríguez-Gutiérrez、María Yolanda Rios
DOI:10.1016/j.bmcl.2012.09.094
日期:2012.12
among them linear di-, tri-, tetra- and pentapeptides and their cyclic analogs. In an attempt to find dipeptides with antimalarial activities we show that linear and cyclicdipeptides, the latter known as diketopiperazines, still retain the fundamental core to preserve antimalarial activity. Thirteen lineardipeptides and ten diketopiperazines were investigated. Eight lineardipeptides showed IC50