Application of a catalytic palladium biaryl synthesis reaction, via C–H functionalization, to the total synthesis of Amaryllidaceae alkaloids
作者:José C. Torres、Angelo C. Pinto、Simon J. Garden
DOI:10.1016/j.tet.2004.08.030
日期:2004.10
The total synthesis of the Amaryllidaceae alkaloids dehydroanhydrolycorine, hippadine, pratosine, anhydrolycorine, assoanine, anhydrolycorin-7-one and oxoassoanine was achieved from the appropriate N-benzylisatin precursors using an intramolecular, palladium catalyzed, dehydrohalogenation, biaryl synthesis reaction to establish the carbon skeleton of the natural products. In order to avoid the formation
使用分子内钯催化的适当的N-苄基异丁烷前驱体,从适当的N-苄基异丁烷前体实现了芳金娘科生物碱脱氢脱水氢化可可碱,马来酸,普拉妥因,脱水赖氨酸,伴生嘌呤,脱水水解素-7-和氧代伴嘌呤的全合成。天然产品。为了避免在环化反应中形成区域异构体,发现有必要将卤素结合在苄基上。7的硼烷还原ħ吡咯并[3,2,1- DE ]菲啶-4,5-二酮衍生物,得到7 ħ吡咯并[3,2,1- DE ] -和4,5-二氢-7 ħ - pyrrolo [3,2,1- de]-菲啶(脱氢脱水氢化可可碱,脱氢伴嘌呤,脱水脱氢赖氨酸和伴氨基嘌呤)。前者很容易用NaCNBH 3还原成后者,得到脱水丝氨酸和伴生嘌呤。然后将这些化合物氧化成脱水水解蛋白-7-一和氧代伴嘌呤,同时可以将硼烷还原产物的相同混合物氧化成马来皮和普拉托因。