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In this study, the first highly chemoselective amidation of Boc and amide groups of N -R- N -Boc arylamides is advanced. This practical and operationally-simple method enables the preparation of either N -aroylureas or imides in good to excellent yields without addition of transition metals. The choice of base plays a significant role in controlling the reactivity of the inequivalent carbonyl groups. The amidation of the Boc group was observed with arylamides, ArCONH 2 , when subjected to KO t Bu while imides were produced with LiOH. DFT studies are employed to explore the divergent mechanisms. It is anticipated that these chemoselective methods will be of interest to the synthetic and medicinal chemistry communities. 

Triarylmethanols are well-known core structures in natural products and pharmacologically relevant compounds. In general, transition metal-based catalysts or highly reactive organometallics are employed for the synthesis of these compounds. Herein, we report the regioselective tandem C(sp 3 )–H arylation/oxidation of diarylmethanes with nitroarenes to generate arylated alcohols. The present method is general, mild, green, and conducted in air at room temperature. Furthermore, use of triarylmethanes as pro-nucleophiles provides straightforward access to select tetraarylmethanes through a cross-dehydrogenative coupling process. 

The imide moiety is a well-known structural motif in bioactive compounds and a useful building block in a variety of processes. Using N -acylglutarimides with MN(SiMe 3 ) 2 and either N -acylpyrroles or aryl esters, an operationally convenient method to produce a wide array of diaryl- and alkyl arylimides is presented. Symmetric imides are also accessible when N -acylglutarimides are employed as acylation reagents under similar reaction conditions. A unique feature of this method stems from the use of two different electrophilic acylating reagents leading to the formation of the unsymmetrical imides with excellent chemoselectivity. 

Chemoselectivity is one of the most challenging issues facing the chemical sciences. In this study, the first highly chemoselective reactions of N -acylpyrroles via either an anionic Fries rearrangement (pyrrole dance) or a C–H functionalization of toluene to provide aryl benzyl ketones are advanced. This efficient and operationally simple approach enables the synthesis of either 2-aroylpyrroles or aryl benzyl ketones in good to excellent yields under transition metal-free conditions. The choice of base plays a crucial role in controlling the chemoselectivity. The aroylation of toluene derivatives was observed with N -acylpyrroles when subjected to KN(SiMe 3 ) 2 , while anionic Fries rearrangement products were produced with LiN(SiMe 3 ) 2 . Surprisingly, cross-over experiments indicate that the anionic Fries rearrangement is an intermolecular process. The aroylation reaction has the advantage over Weinreb amide chemistry in that it does not require preformed organometallic reagents or cryogenic temperatures. 

The use of nitroarenes as amino sources in synthesis is challenging. Herein is reported an unusual, straightforward, and transition metal-free method for the net [3 + 2]-cycloaddition reaction of 2-azaallyl anions with nitroarenes. The products of this reaction are diverse 2,5-dihydro-1,2,4-oxadiazoles (>40 examples, up to 95% yield). This method does not require an external reductant to reduce nitroarenes, nor does it employ nitrosoarenes, which are often used in N–O cycloadditions. Instead, it is proposed that the 2-azaallyl anions, which behave as super electron donors (SEDs), deliver an electron to the nitroarene to generate a nitroarene radical anion. A downstream 2-azaallyl radical coupling with a newly formed nitrosoarene is followed by ring closure to afford the observed products. This proposed reaction pathway is supported by computational studies and experimental evidence. Overall, this method uses readily available materials, is green, and exhibits a broad scope.

 

In the last 20 years, efficient transition metal catalysts for the α‐arylation of enolates have been introduced. Despite the popularity and utility of these reactions, there remains room for improvement (reduced costs, elimination of transition metals and specialized ligands). Herein is reported a general, scalable and green method for aroylation of simple diarylmethane pronucleophiles through direct acyl C−N cleavage ofN‐Bn−N‐Boc arylamides andN‐acylpyrroles under transition metal‐free conditions. Importantly, a 1 : 1 ratio of the amide to the pronucleophile is employed. Unlike use of Weinreb amides, this method avoids preformed organometallics (organolithium and Grignard reagents) and does not employ cryogenic temperatures, which are difficult and costly to achieve on scale. The operationally simple protocol provides straightforward access to a variety of sterically and electronically diverse 1,2,2‐triarylethanones, a group of compounds with high‐value in medicinal chemistry.

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Olfactory responses to single odors have been well characterized but in reality we are continually presented with complex mixtures of odors. We performed high-throughput analysis of single-cell responses to odor blends using Swept Confocally Aligned Planar Excitation (SCAPE) microscopy of intact mouse olfactory epithelium, imaging ~10,000 olfactory sensory neurons in parallel. In large numbers of responding cells, mixtures of odors did not elicit a simple sum of the responses to individual components of the blend. Instead, many neurons exhibited either antagonism or enhancement of their response in the presence of another odor. All eight odors tested acted as both agonists and antagonists at different receptors. We propose that this peripheral modulation of responses increases the capacity of the olfactory system to distinguish complex odor mixtures.