钯催化的多步串联羰基化/N-脱烷基化反应合成靛酸酐衍生物

chem有机方法2023-07-227.9K+

文献¹报道了一种新型高效的合成靛酸酐衍生物的方法，即钯催化的多步串联羰基化/N-脱烷基化反应。该反应具有良好的官能团耐受性，且起始原料简单易得；同时也为具有生物和药用价值的Evodiamine提供了一种简便的合成方法。

靛酸酐衍生物的脱羧转化

底物范围考察

其它类型的N`N-二烷基类底物的考察

讨论:从上面三类底物的反应情况可以看出，当N上取代基位阻增大时，反应效果有变差的趋势；且当N上取代基为苄基类时，脱落的片段会转变为相应的醛。

可能存在的机理

General Procedure

The mixture of 1 (0.2 mmol,1.0 eq), Cu(OAc)₂ (0.2 mmol, 1.0eq) and PdCl₂(CH₃CN)₂(0.02 mmol, 0.1 eq) was stirred in PhMe/DMF(10:1) (2.5 mL/mmol) inan oil bath at 100 ^oC, in a 20 mL tube with a balloon CO/O2 (1:1).When the reaction was completed (detected by TLC), the mixture was cooled to RT. The reaction was quenched with H₂O (10 mL) and extracted with EA(3×10mL) or CH₂Cl₂ (3 × 10 mL). The combined organic layers were dried over anhydrous Na₂SO₄ and then evaporated in vacuo. The residue was purified by column chromatographyon silica gel to afford the corresponding isatoic anhydrides 2 with CH₂Cl₂/EA as the eluent.

主要试剂

PdCl₂(CH₃CN)₂	CAS号: 14592-56-4
Cu(OAc)₂	CAS号142-71-2

参考文献

1	10.1021/acs.joc.9b02771

本文地址：https://www.chemrss.com/1824.html