N-methylamines are an important class of amines that find increasing applications in chemical, pharmaceutical, agrochemical and material industries. For their preparation, reductive N-methylation reactions employing CO₂, formic acid, and (para)formaldehyde as renewable C1 sources have shown outstanding advantages compared to traditional methylation reagents, on standpoint of sustainable chemical processes. In this respect, significant efforts have been made on the synthesis of N-methylamines by catalytic reductive aminations. In this review, we discuss the recent advancements toward the base metal-catalyzed reductive amination of amines and nitroarenes including nitriles using CO₂, formic acid, and (para)formaldehyde for the synthesis of diverse N-methylated products.

N-甲胺是一类重要的胺，在化学、制药、农业化学和材料工业中的应用越来越多。对于它们的制备，从可持续化学过程的角度来看，使用 CO ₂、甲酸和（多）甲醛作为可再生 C1 源的还原性N-甲基化反应与传统甲基化试剂相比显示出突出的优势。在这方面，已经在通过催化还原胺化合成N-甲胺方面做出了重大努力。在这篇综述中，我们讨论了使用 CO ₂对胺和硝基芳烃（包括腈）进行贱金属催化还原胺化的最新进展、甲酸和（对）甲醛用于合成各种N-甲基化产物。