ZuschriftenScheme 2. Substrate scope.[a] The reactions were conducted using 0.5 mmol of the amides 1.Y ields of the isolated alcohols 2 and amines 3 are given.[b] The reaction was conducted using 5equiv of NaH, 2equiv of ZnI 2 and 2equiv of NaI.[c] The reaction was conducted using 7equiv of NaH and 3.5 equiv of ZnCl 2 .[d] 1aj > 98 %ee; 2aj > 97 %ee; 3aj > 98 % ee as measured by the Mosher method (see the Supporting Information).[e] Amine 3ak was formed in 35 %yield. [f]Amine 3al was formed in 31 %yield. Bn = benzyl, Ph = phenyl, TIPS = triisopropylsilyl.Scheme 5. DFT calculations for model reactions of benzamide with (ZnH 2 ) 2 or (ZnHCl) 2 species. Energy changes and bond lengths at the wB97XD/SDD&6-31 + G* (scrf = smd, THF) level of theory are shown in kcal mol À1 and ,respectively.

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.

No abstract

This study reports on successful synthesis of carbon dots (CDs), nitrogen-doped zinc oxide (N-ZnO), and N-ZnO/CD nanocomposites as photocatalysts for degradation of methylene blue. The first part was the synthesis of CDs utilizing a precursor from soybean and ethylenediamine as a dopant by a hydrothermal method. The second part was the synthesis of N-ZnO with urea as the nitrogen dopant carried out by a calcination method in a furnace at 500 °C for 2 h in an N2 atmosphere (5 °C min–1). The third part was the synthesis of N-ZnO/CD nanocomposites. The characteristics of CDs, N-ZnO, and N-ZnO/CD nanocomposites were analyzed through Fourier transform infrared (FTIR), UV–vis absorbance, photoluminescence (PL), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), thermal gravimetry analysis (TGA), field-emission scanning electron microscopy energy-dispersive spectroscopy (FESEM EDS), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) analysis. Based on the HR-TEM analysis, the CDs had a spherical shape with an average particle size of 4.249 nm. Meanwhile, based on the XRD and HR-TEM characterization, the N-ZnO and N-ZnO/CD nanocomposites have wurtzite hexagonal structures. The materials of N-ZnO and N-ZnO/CD show increased adsorption in the visible light region and low energy gap E g. The E g values of N-ZnO and N-ZnO/CDs were found to be 2.95 and 2.81 eV, respectively, whereas the surface area (S BET) values 3.827 m2 g–1 (N-ZnO) and 3.757 m2 g–1(N-ZnO/CDs) belonged to the microporous structure. In the last part, the photocatalysts of CDs, N-ZnO, and N-ZnO/CD nanocomposites were used for degradation of MB (10 ppm) under UV-B light irradiation pH = 7.04 (neutral) for 60 min at room temperature. The N-ZnO/CD nanocomposites showed a photodegradation efficiency of 83.4% with a kinetic rate of 0.0299 min–1 higher than N-ZnO and CDs. The XRD analysis and FESEM EDS of the N-ZnO/CDs before and after three cycles confirm the stability of the photocatalyst with an MB degradation of 58.2%. These results have clearly shown that the N-ZnO/CD nanocomposites could be used as an ideal photocatalytic material for the decolorization of organic compounds in wastewater.

New protocols for controlled reduction of carboxamides to either alcohols or amines were established using ac ombination of sodium hydride (NaH) and zinc halides (ZnX 2 ). Use of ad ifferent halide on ZnX 2 dictates the selectivity,w herein the NaH-ZnI 2 system delivers alcohols and NaH-ZnCl 2 gives amines.Extensive mechanistic studies by experimental and theoretical approaches imply that polymeric zinc hydride (ZnH 2 ) 1 is responsible for alcohol formation, whereas dimeric zinc chloride hydride (HÀZnÀCl) 2 is the key species for the production of amines.