A Novel [3+2] Cycloaddition Approach to Nitrogen Heterocycles via Phosphine-Catalyzed Reactions of 2,3-Butadienoates or 2-Butynoates and Dimethyl Acetylenedicarboxylate with Imines: A Convenient Synthesis of Pentabromopseudilin
摘要:
The reactivity of a new three carbon synthon, generated in situ from the reaction of 2,3-butadienoates or 2-butynoates with an appropriate phosphine as the catalyst, toward the electron deficient imines is described. Triphenylphosphine-catalyzed reaction of-methyl a,3-butadienoate with N-sulfonylimines gave the single [3+2] cycloadduct in excellent yield; tributylphosphine-catalyzed reaction of methyl 2,3-butadienoate or 2-butynoate with N-tosylimines afforded the corresponding [3+2] cycloadduct as the major product along with a small amount of the three components adduct. Aliphatic N-tosylimines gave moderate yield for this reaction. In addition, a new phosphine-catalyzed cyclization reaction of dimethyl acetylenedicarboxylate with N-tosylimines is also described. A:reaction mechanism is proposed. Further elaborations of the cycloaddition products and the synthesis of pentabromopseudilin using this method are exemplified.
Phosphine-catalyzed [3+2] cycloaddition reaction of methyl 2,3-butadienoate and N-tosylimines. A novel approach to nitrogen heterocycles
摘要:
In the presence of a catalytic amount of triphenylphosphine, methyl 2,3-butadienoate smoothly reacted with aromatic or heteroaromatic N-tosylimines at room temperature to afford the [3+2] cycloaddition product in excellent yield. (C) 1997 Elsevier Science Ltd.
Phosphine-catalyzed [3+2] cycloaddition reaction of methyl 2,3-butadienoate and N-tosylimines. A novel approach to nitrogen heterocycles
作者:Zhenrong Xu、Xiyan Lu
DOI:10.1016/s0040-4039(97)00656-4
日期:1997.5
In the presence of a catalytic amount of triphenylphosphine, methyl 2,3-butadienoate smoothly reacted with aromatic or heteroaromatic N-tosylimines at room temperature to afford the [3+2] cycloaddition product in excellent yield. (C) 1997 Elsevier Science Ltd.
A Novel [3+2] Cycloaddition Approach to Nitrogen Heterocycles via Phosphine-Catalyzed Reactions of 2,3-Butadienoates or 2-Butynoates and Dimethyl Acetylenedicarboxylate with Imines: A Convenient Synthesis of Pentabromopseudilin
作者:Zhenrong Xu、Xiyan Lu
DOI:10.1021/jo9723063
日期:1998.7.1
The reactivity of a new three carbon synthon, generated in situ from the reaction of 2,3-butadienoates or 2-butynoates with an appropriate phosphine as the catalyst, toward the electron deficient imines is described. Triphenylphosphine-catalyzed reaction of-methyl a,3-butadienoate with N-sulfonylimines gave the single [3+2] cycloadduct in excellent yield; tributylphosphine-catalyzed reaction of methyl 2,3-butadienoate or 2-butynoate with N-tosylimines afforded the corresponding [3+2] cycloadduct as the major product along with a small amount of the three components adduct. Aliphatic N-tosylimines gave moderate yield for this reaction. In addition, a new phosphine-catalyzed cyclization reaction of dimethyl acetylenedicarboxylate with N-tosylimines is also described. A:reaction mechanism is proposed. Further elaborations of the cycloaddition products and the synthesis of pentabromopseudilin using this method are exemplified.