Nucleophilic additions to (4 S )-1-alkylidene-2,4-dihydro-1 H -pyrazino[2,1- b ]quinazoline-3,6-diones
作者:Marı́a Luisa Heredia、Elena de la Cuesta、Carmen Avendaño
DOI:10.1016/s0040-4020(01)00046-1
日期:2001.3
reactivity against amines or Grignard reagents under copper(I) catalysis, but efficient additions to the exocyclic double bond took place with mercaptides or stabilized carbanions. Regio- and diastereoselective addition of organometallic reagents occurred at the C(3)-position and, in 1-methylene derivatives, these reactions were followed by a rearrangement of the intermediate oxy-anion to give pyrido[2,1-b]quinazolines
标题化合物为双氢氨基酸模板的研究表明,它们在铜(I)催化下对胺或格氏试剂缺乏反应性,但硫醇盐或稳定的碳负离子有效地加到了环外双键上。在C(3)-位发生有机金属试剂的区域和非对映选择性加成,在1-亚甲基衍生物中,这些反应之后是中间氧阴离子的重排,从而得到吡啶并[2,1- b ]喹唑啉。
1-Bromo-2,4-dihydro-1H-pyrazino[2,1-b]quinazoline-3,6-diones as α-bromoglycine templates
作者:Marı́a Luisa Heredia、Marı́a Fernández、Elena de la Cuesta、Carmen Avendaño
DOI:10.1016/s0957-4166(01)00067-2
日期:2001.3
The title compounds behaved as α-bromoglycine templates. Radical substitutions and SN1-type nucleophilic additions proceeded with retention of stereochemistry, while SN2-type displacements occurred with net inversion of configuration. A homocoupling product was obtained in attempting a Stille cross-coupling reaction.
标题化合物表现为α-溴甘氨酸模板。自由基取代和S N 1型亲核加成继续保留立体化学,而S N 2型置换发生净构型倒置。在尝试进行Stille交叉偶联反应时获得了均偶联产物。