The Meyer-Schuster rearrangement reaction has been known for almost a hundred years. It has been used to prepare unsaturated aldehydes, ketones, and even esters from propargyl alcohols. Thirty years ago, the same reaction was found to produce also α-halogenated aldehydes and ketones under suitable conditions. In the last thirty years, several methods have been developed utilizing the Meyer-Schuster rearrangement in the synthesis of halogenated building blocks for use in synthetic chemistry. In this perspective, we describe the progress in the field.

Conventionally, N-bromosuccinimide (NBS) is a brominating and oxidizing reagent in organic synthesis. In our research on N-haloimides in organic transformation, we proposed the concept of utilizing N-haloimides like NBS as an amination reagent, i.e., direct incorporation of imido unit to the target molecules to achieve amination, with the assistance of positive halogen(I). In this paper, we would like to summarize the amination of various fundamental substrates with N-haloimides as the amination reagents. We have developed an N-haloimide-DBU (Lewis base activator) combination system, which affords halogen bonding complex and subsequent ion pair intermediate via halogen transfer. All these reactions feature convenient and readily available reagents, mild conditions, simple execution, broad halogen scope, high efficiency and metal-free. The utilization of N-haloimides as versatile aminating reagents has been demonstrated and further application of the synthetic protocol for the preparation of bioactive and optical materials is expected.