Simple Metal‐Free Direct Reductive Amination Using Hydrosilatrane to Form Secondary and Tertiary Amines

Abstract

This work describes the use of cheap, safe, and easy‐to‐handle hydrosilatrane as the reductant in direct reductive amination reactions. This efficient method enables a facile, metal‐free access to secondary and tertiary amines from a wide range of aldehydes and ketones, with the synthesis of tertiary amines requiring no additives at all. This reaction demonstrates excellent functional group tolerance, chemoselectivity, and scalability.magnified image

One-Pot Reductive Acetylation of Aldehydes using 1-Hydrosilatrane in Acetic Acid

“…Our research program has led to the development of a direct route for the reduction of aldehydes and ketones to their corresponding alcohols 20,21 and direct reductive aminations of aldehydes and ketones in the presence of an amine. 22 1-Hydrosilatrane is an attractive reducing agent because it is air-and moisture-stable, inexpensive, and simple to synthesize. 21 While most of our work has shown silatrane reduction utilizing a Lewis base activator, experimental observations indicate that weak Brønsted acids also facilitate the reduction of aldehydes with no observed ether formation.…”

Computational investigation of the control of the thermodynamics and microkinetics of the reductive amination reaction by solvent coordination and a co-catalyst

“…Starting from the initially protonated reaction paths which are kinetically different, the nucleophilic additions are feasible. However, both paths are giving the same intermediate (11) in the end. Later, the reaction will go through 5c and yield a long chain amine as the nal product.…”

“…Several metal-based catalyst systems (such as Co 3 O 4 /H 2 and SnCl 2 /reducing agent) are mentioned in the literature as suitable candidates for this process. 11,18,19 There are also several successful experimental and computational reports on the functionalization of several amines via intra-and intermolecular cyclization reactions in a redox neutral way. [20][21][22] In addition, they give some evidence for the formation of ylide intermediates which suggests that the reaction can also proceed via an alternative route and would not necessarily involve the formation of iminium ions.…”

Reactivity of 1-allylsilatrane in ruthenium-catalyzed silylative coupling with olefins – mechanistic considerations

“…Silatranes make a widely studied class of organosilicon compounds characterized by cage tricyclic structure, pentacoordinate silicon center with donor-acceptor transannular Si ← N bond, and interesting biological properties [1][2][3]. In the last three decades, research on silatranes covered several areas, including organic and organometallic synthesis [4][5][6], materials chemistry [7][8][9] as well as biochemistry and medicine [10][11][12][13] Given the variety of silatrane derivatives, allylsilatranes are hardly explored, which stands in stark contrast to the wide range of applications of allylsilanes in organic synthesis (e.g., in allylation of carbonyl compounds or olefin metathesis, for review see [14]). 1-Allylsilatrane (or allylsilatrane) 1 is the simplest representative of allylsubstituted silatranes (Figure 1).…”