无需乙烯，5分钟室温下实现氨酯交换得到酰胺

乙酰键是一种非常类似于的一种工程学键，广泛存在于天然催化反应和工业产品当中，例如复合物蛋白、农药、化学材料和药物，氢化乙酰最重要的有机催化之一。目前乙酰的最类似于催化方法就是羧酸和羟基的硫酸丙酮，这就能够另外投身丙酮剂或硫酸剂。实际上由醇和羟基进行羟基醇交换氢化乙酰是最理想的方法，但是这种转化多半条件苛刻，催化时间长。

早期在六十年代30年代，有文献美联社醇与氨实际上氨解得到宰乙酰。后来加以改进并广泛用以催化工程学和药物催化，多半但会此催化非常缓慢，但在某些催化当中可以使用NaNH2代替NH3实际上在二氯甲烷当中与醇催化或者AlMe3等强碱有助于的羟基醇交换氢化乙酰取得很好的敏感度。

近期在 《nature communications》上美联社了一篇，利用酰硼烷钠 (NaNH2BH3 , NaAB )与醇催化氢化宰乙酰和仲乙酰的方法，在室温下， 5分钟内定量过渡到除此以外的宰乙酰，必需任何过氧化氢。此外，NaMeNHBH3 (NaMeAB) 也可用以在相同条件下催化N-Me 仲乙酰【 Nat. Commun. , 2021, 2, 5964】。

催化机理

催化操作

General method for the synthesis of primary or secondary amides. Under N2 atmosphere, NaRNHBH3 (R = H, Me) (1.20 mmol) was put into a 10 mL flask which was connected to a Schlenk line and then 5 mL of THF was added. Then 0.5 mmol of substrate ester was added. The reaction mixture was stirred at room temperature and monitored by 1H NMR spectroscopy or TLC. After 5 min, the substrate ester was consumed, and then the solvent was pumped out. Next, the mixed solvent of CH2Cl2 and n-hexane (volume ratio of 10:1) was added to extract RNH2BH3, while Na[R’CONRBH3] (R’ = alkyl, aryl; R = H, Me) and other boroncontaining compounds are left in the residual. Then, add 15 mL water into the flask and stir for 15 min. Addition of ethyl acetate extract the product (7–8 times) and the organic phases are collected and dried. The amide products with high purity and yield were obtained.

参考资料

Efficient synthesis of primary and secondary amides via reacting esters with alkali metal amidoboranes；Yu Guo , Ruo-Ya Wang, Jia-Xin Kang , Yan-Na Ma, Cong-Qiao Xu , Jun Li✉ Company Xuenian Chen✉； Nat. Commun. , 2021, 2, 5964。