Sodium hydride (NaH) is widely used as a Brønsted base in chemical synthesis and reacts with various Brønsted acids, whereas it rarely behaves as a reducing reagent through delivery of the hydride to polar π electrophiles. This study presents a series of reduction reactions of nitriles, amides, and imines as enabled by NaH in the presence of LiI or NaI. This remarkably simple protocol endows NaH with unprecedented and unique hydride‐donor chemical reactivity.
A new and concise protocol for selective reduction of N,N‐dimethylamides into aldehydes was established using sodium hydride (NaH) in the presence of sodium iodide (NaI) under mild reaction conditions. The present protocol with the NaH‐NaI composite allows for reduction of not only aromatic and heteroaromatic but also aliphatic N,N‐dimethylamides with wide substituent compatibility. Retention of α‐chirality in the reduction of α‐enantioriched amides was accomplished. Use of sodium deuteride (NaD) offers a new step‐economical alternative to prepare deuterated aldehydes with high deuterium incorporation rate. The NaH‐NaI composite exhibits unique chemoselectivity for reduction of N,N‐dimethylamides over ketones.
Sodium hydride (NaH) has been commonly used as a Brønsted base in chemical syntheses, while it has rarely been employed to add hydride (H(-) ) to unsaturated electrophiles. We previously developed a procedure to activate NaH through the addition of a soluble iodide source and found that the new NaH-NaI composite can effect even stereoselective nucleophilic hydride reductions of nitriles, imines, and carbonyl compounds. In this work, we report that mixing NaH with NaI or LiI in tetrahydrofuran (THF) as a solvent provides a new inorganic composite, which consists of NaI interspersed with activated NaH, as revealed by powder X-ray diffraction, and both solid-state NMR and X-ray photoelectron spectroscopies. DFT calculations imply that this remarkably simple inorganic composite, which is comprised of NaH and NaI, gains nucleophilic hydridic character similar to covalent hydrides, resulting in unprecedented and unique hydride donor chemical reactivity.
A new protocol for amide-directed ortho and lateral C-H sodiation is enabled by sodium hydride (NaH) in the presence of either sodium iodide (NaI) or lithium iodide (LiI). The transient organosodium intermediates could be transformed into functionalized aromatic compounds.
Sodium hydride (NaH) is widely used as aBrønsted base in chemical synthesis and reacts with various Brønsted acids,whereas it rarely behaves as areducing reagent through delivery of the hydride to polar p electrophiles.T his study presents aseries of reduction reactions of nitriles,amides,and imines as enabled by NaH in the presence of LiI or NaI. This remarkably simple protocol endows NaH with unprecedented and unique hydride-donor chemical reactivity.Hydridereductionofpolarp electrophiles,such as carbonyl compounds,c arbonitriles,a nd imines,i so ne of the most fundamental and important molecular transformations in chemical synthesis.[1] In this context, av ariety of covalent hydrides,s uch as borane,a lane,m etal borohydrides,m etal aluminum hydrides,and silanes,have often been employed as the reagents of choice for stereo-, regio-, and chemoselective hydride-transfer processes.Bycontrast, alkali-metal hydrides have rarely been employed as hydride sources;i nstead, they are used almost exclusively as strong Brønsted bases for deprotonation reactions in chemical synthesis. [2,3] Herein, we report that NaH can act as ahydride donor in reactions with nitriles,a mides,a nd imines when it has been subjected to simple solvothermal treatment with LiI or NaI in THF.O f particular interest is the outcome of hydride reduction reactions of nitriles and amides,w hich deliver the corresponding alkanes (through decyanation) and aldehydes, respectively.During the course of our experiments on the a-methylation of diphenylacetonitrile (1)t op repare tertiary carbonitrile 2a,weinvestigated its reaction with NaH (3 equiv) and MeI (1.2 equiv) in THF (85 8 8Ci nas ealed tube;S cheme 1). Although the desired tertiary nitrile 2a was isolated in 74 % yield, we were surprised to observe the formation of 1,1-diphenylethane (3a)i n2 5% yield as aside product. Assuming that 3a was formed by the decyanation of nitrile 2a,w e expected that this decyanation reaction could be generalized to am ore versatile synthetic strategy
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.