关于氨硼烷（NH3·BH3）和羧酸酯反应的文章，我们之前分享过一篇还原：酯的另类还原，产物非醛非醇，有点厉害！
当时就觉得这个机理很有意思，通过一个路易斯酸束缚，羧酸酯被砍了两刀，然后就产生了醚！
记得当时还有人问我能不能用氨硼烷做酰胺化，当时直接否了，因为这个化合物氮原子的孤对电子会填入硼原子的空轨道，形成 N→B 配位键，基本上没什么亲核性。
不过最近被打脸了，因为亲核性是可以被构造的。
来自郑州大学的研究人员发现， 仅仅需要加入一个强的非亲核性碱，就可以实现氨硼烷和酯基的酰胺化反应。
这是氨硼烷首次被作为氮源而非氢硼化的应用！
且该方法无论是芳香酯，脂肪酯，还是杂环酯均可适配，大多数收率都在80%以上，多数后处理仅过滤就能得到产物！
一些商业药物和天然产物的合成上同样优势明显；
反应机理如下，就是类似传统加成消除的机理；
实验步骤部分：
1. General Procedure for the Synthesis of Primary Amides
Ammonia borane (0.44 mmol, 1.1 equiv) was added to a 10 mL Schlenk-tube and then 4 mL of THF, 2 M of NaHMDS (Sodium hexamethyldisilazane, 0.6 mmol, 1.5 equiv) and methyl benzoate (0.4 mmol, 1 equiv) were sequentially added to this reaction system. Next, the mixture was stirred for 15 min under nitrogen at room temperature. After completion of the reaction, the resulting mixture was quenched by addition of H2O (2 mL), and extracted with DCM (3×10 mL). The organic layers were combined and dried with anhydrous Na2SO4 and concentrated under reduced pressure, the resulting residue was purified by simple filtration and dried in vacuo.
2. General Procedure for the Synthesis of 5H-dibenzo[b,f]azepine-5-carboxylate
A mixture of 5H-dibenzo[b,f]azepine (5.0 mmol, 0.97 g), DBU (1,8-diazabicyclo[5.4.0]undec-7-ene, 1.5 mmol, 0.23 g) and methyl carbonochloridate (10.0 mmol, 13 mL) were sequentially added to the reaction system under nitrogen and stirred at 110 °C for 3 h. After the mixture was cooled down to room temperature, the solution was diluted with DCM (50 mL). Afterward, the mixture was basified to pH 8 with NaHCO3 solution at 0 °C. After it was stirred at room temperature for 1 h, the organic layer was finally washed with brine (80 mL) and dried over anhydrous Na2SO4. The organic layer was evaporated under reduced pressure. The residue was purified by silica gel chromatography by using petroleum ether/ethyl acetate to afford 5Hdibenzo[b,f]azepine-5-carboxylate.
3. General Procedure for α-alkyl ester （手性 α- 烷基酯底物在反应中易发生消旋）
参考文献：Li, X. Y.; Kang, J. X.; Han, H.; Ma, Y. N.; Liu, Z.; Chen, X., Rapid Synthesis of Primary Amides Using Ammonia Borane. J Org Chem 2025, 90 (4), 1720-1726.
