Transition-Metal-Free Base-Promoted Deaminative Coupling of Gramines with Aminomaleimides

Metal-free amination of alkenes based on maleimides

A metal-free amination of alkenes based on maleimides has been developed. This method features mild reaction conditions and broad substrate scope, and aminomaleimides with EWGs have been synthesized in up to 99% yield. The gram-scale reaction and successful derivatization of the products further demonstrate the applicability of this methodology.

Asymmetric Synthesis of Unprotected Tryptophan Derivatives Using Gramines via Ni(II) Complexes

We herein report the synthesis of substituted tryptophans using Ni(II) complexes of glycine and gramines. This reaction proceeds under operationally convenient and mild conditions, using inexpensive, nontoxic, and easily accessible reagents. The reactions feature high yields and virtually complete thermodynamically controlled diastereoselectivity, providing a convenient method for the synthesis of tailor-made tryptophans.

Assembly of Diverse Allenes via Activator-Free Palladium-Catalyzed Regioselective γ-Arylation of Propargylamines with Boronic Acids

Controlling the reaction selectivity to achieve a precision synthesis is a constant concern for chemists. Here, we report a palladium-catalyzed deaminative coupling of propargylamines with arylboronic acids to generate allene skeletons. Importantly, this approach allows the regioselective γ-arylation of unactivated propargyl tertiary amines to access various allenes in the absence of amino-activating reagents. We present a wide range of propargylamines and boronic acids and demonstrate the synthetic application of the target products to construct valuable compounds.

Ynone Promoted Deaminative Coupling of Gramines with C- and N-Nucleophiles

The deaminative coupling of gramines with nucleophiles represents a versatile approach for structure diversification, but often involves non innocent conditions and/or reagents. Here a new acetylenic reagent 2 is developed for the C-N bond activation of gramines and their in situ coupling with C- and N-centered nucleophiles. Using the new acid/base- and redox-neutral ynone reagent 2 the coupling reactions proceed exceedingly as exemplified by the synthesis of several indol-3-ylmethyl derivatives, including new indole-benzodiazepine and indole-hydrazone conjugates.

Cooperative Triple Catalysis Enables Deaminative α-Indolmethylation of Carbonyl Compounds with Gramines

α-Functionalization of carbonyl compounds is an important reaction in synthetic chemistry. However, the development of novel synthetic strategies to realize this reaction is challenging. This study describes the α-indolmethylation of carbonyl compounds using cooperative copper, amine, and hydrogen-bond catalysis. This reaction provides a novel and efficient strategy for developing indolmethylated carbonyl compounds by deaminative coupling of gramines.