α‐Amination of Carbonyl Compounds by Using Hypervalent Iodine‐Based Aminating Reagents Containing a Transferable (Diarylmethylene)amino Group

Abstract Hypervalent iodine‐based aminating reagents containing a transferable (diarylmethylene)amino group can be used for the α‐amination of simple carbonyl compounds such as esters, amides, and ketones in the presence of a lithium base. The (diarylmethylene)amino groups of the products can be readily modified, thus providing access to primary amines and diarylmethylamines. The developed method features transition‐metal‐free conditions and a simple one‐pot procedure without the need to prepare enolate equivalents separately, thus offering a general and practical approach to the synthesis of a wide variety of α‐amino carbonyl compounds. Experimental mechanistic investigations indicate that this amination proceeds through a unique radical coupling of an α‐carbonyl radical with an iminyl radical; they are generated through a single‐electron transfer between a lithium enolate and the hypervalent iodine reagent.