Smiles-Rearrangement-Based One-Pot Synthesis of Diarylacetylenes from Benzylic Sulfones and Methyl Benzoates Mediated by LiN(SiMe)/KN(SiMe).

The one-pot synthesis of diphenylacetylene by the reaction of methyl benzoate with 1-(benzylsulfonyl)-3,5-di(trifluoromethyl)benzene was developed. The combination of LiN(SiMe) and KN(SiMe) is key to promoting the reaction. Simply combining methyl benzoate, 1-(benzylsulfonyl)-3,5-di(trifluoromethyl)benzene, LiN(SiMe), and KN(SiMe) can produce a variety of diaryl acetylenes (28 examples, 18-70% yields).

Cobalt-Catalyzed Three-Component Alkyl Arylation of Acrylates with Alkyl Iodides and Aryl Grignard Reagents.

A highly regioselective cobalt-catalyzed three-component alkyl arylation of acrylates with alkyl iodides and aryl Grignard reagents has been established. The reaction efficiently provides an alternative strategy for the construction of α-aryl esters with a broad substrate scope and good yields under mild conditions. The practical applicability of this protocol is shown by the scaled-up reaction and further transformations of the products.

Nickel/Photoredox-Catalyzed Asymmetric Three-Component Cross-Coupling To Access Enantioenriched 1,1-Diaryl(heteroaryl)alkanes.

An enantioselective 1,2-dicarbofunctionalization of vinyl (hetero)arenes with alkyl bromides and aryl bromides through nickel/photoredox catalysis is described. This three-component enantioselective domino alkyl arylation of vinyl (hetero)arenes could generate a diverse array of enantioenriched 1,1-diaryl(heteroaryl)alkanes with good to excellent yields (up to 88%) and high enantioselectivities (up to 99% ). This transformation could proceed well under mild conditions with excellent chemo- and regioselectivity due to the avoidance of the use of air- and moisture-sensitive organometallic reagents and stoichiometric metal reductants.

HOO as the Chain Carrier for the Autocatalytic Photooxidation of Benzylic Alcohols.

The oxidation of benzylic alcohols is an important transformation in modern organic synthesis. A plethora of photoredox protocols have been developed to achieve the aerobic oxidation of alcohols into carbonyls. Recently, several groups described that ultraviolet (UV) or purple light can initiate the aerobic oxidation of benzylic alcohols in the absence of an external catalyst, and depicted different mechanisms involving the photoinduction of O as a critical reactive oxygen species (ROS).

One-Pot Synthesis of Indolin-3-ones Mediated by LiN(SiMe)/CsF.

Indolin-3-ones are essential heterocycles with wide-ranging biological activities and medicinal values, and therefore, efficient approaches to their synthesis remain in demand. Herein, a novel and operationally simple method to generate indolin-3-ones is reported by using a tandem reaction of -methylbenzylamines and methyl 2-fluorobenzoates mediated by the LiN(SiMe) and CsF system (34 examples, 30-85% yields). The synthesis of C2-quaternary indolin-3-one further demonstrated the potential practicability of these tandem reactions.

Base-Promoted Synthesis of Isoquinolines through a Tandem Reaction of 2-Methyl-arylaldehydes and Nitriles.

A convenient method for preparing 3-aryl isoquinolines via a base-promoted tandem reaction is presented. Simply combining commercially available 2-methyl-arylaldehydes, benzonitriles, NaN(SiMe), and CsCO enabled the synthesis of a variety of isoquinolines (23 examples, ≤90% yield). Among the syntheses of isoquinolines, the transition metal-free method described here is straightforward, practical, and operationally simple.

Synthesis of Homoallylamines Enabled by Cobalt or Palladium Catalyzed Allylic Substitution of Azaarylmethylamines.

Pd(OAc)/Nixantphos or CoI/Nixantphos catalyzed allylic substitutions with weakly acidic C(sp)-H bonds of azaarylmethylamines are described. This method facilitates access to various kinds of heteroaryl rings containing homoallylamines (39 examples, 30-98% yields) with excellent functional group tolerance and diastereoselectivity. Compared with the Pd/Nixantphos complex, the Co/Nixantphos catalysis could obtain the cyclic products with good to excellent diastereoselectivities.

Nickel-Catalyzed Reductive Arylation of α-Bromo Sulfoxide.

A nickel-catalyzed cross-electrophile coupling of aryl iodides with α-bromo sulfoxide to access a diverse array of aryl benzyl sulfoxides has been discovered. These reactions occurred under mild conditions with excellent functional group tolerance so that optically enriched sulfoxides could be coupled with aryl iodides, generating corresponding sulfoxides with excellent stereochemical integrity. Furthermore, the scalability of this transformation was demonstrated.

Nickel/photoredox-catalyzed enantioselective arylation of α-chloro thioesters.

The first dual nickel/photoredox-catalyzed enantioselective reductive cross-coupling of racemic α-chloro thioesters with aryl iodides has been developed. This strategy avoids the need for organometallic reagents or stoichiometric metal reductants. This reaction could tolerate a wide range of substrate scope with excellent reactivity and high enantioselectivities (up to 91% ee) to access a variety of chiral α-aryl thioesters.

A Tandem Madelung Indole Synthesis Mediated by a LiN(SiMe)/CsF System.

A tandem Madelung indole synthesis by the reaction of methyl benzoate and -methyl--toluidine has been discovered. The combination of LiN(SiMe) with CsF is the key factor, which secures the high efficiency of such tandem transformations. Simply combining methyl benzoate, -methyl--toluidine LiN(SiMe), and CsF generated a diverse array of -methyl-2-phenylindoles (31 examples, 50-90% yields).

Alkali-Amide-Catalyzed One-Pot Aminoallylation of Aldehydes with Allylbenzenes.

The deprotonation of allylbenzene was successfully demonstrated with a catalytic alkali amide base (NaN(SiMe)). The deprotonated allyl anion could be trapped by in situ generated -(trimethylsilyl) aldimines to provide value-added homoallylic amines (39 examples, 68-98% yields) in a one-pot manner with excellent liner selectivity. Compared with the previously reported method for the synthesis of homoallylic amines, this method does not need to use the preinstalled protection groups on the imines, which need to be removed after the reaction to obtain the N-H free homoallylic amine derivatives.

Synthesis of Indoles via Domino Reactions of 2-Methoxytoluene and Nitriles.

2-Arylindoles are privileged structures widely present in biologically active molecules. New sustainable synthetic routes toward their synthesis are, therefore, in high demand. Herein, a mixed base-promoted benzylic C-H deprotonation of commercially available -anisoles, addition of the resulting anion to benzonitriles, and SAr to displace the methoxy group provide indoles.

Nickel-Catalyzed Cross-Electrophile Coupling of 1,2,3-Benzotriazin-4(3)-ones with Aryl Bromides.

The nickel-catalyzed cross-electrophile coupling of 1,2,3-benzotriazin-4(3)-ones with aryl bromides to generate a diverse array of -arylated benzamide derivatives has been developed. The reaction displayed good functional group tolerance with Zn as the reductant. The key to this transformation is the ring opening of benzotriazinones, which undergo a denitrogenative process to obtain various benzamide derivatives (29 examples, 42-93% yield).

One-Pot Rapid Access to Benzyl Silanes, Germanes, and Stannanes from Toluenes Mediated by a LiN(SiMe)/CsCl System.

Organo-silanes, germanes, and stannanes are considered to be conducive to the development of cross-coupling reactions because they are stable, nontoxic, and easy to handle. Using feedstock toluenes, one-pot direct benzylic C-H silylations, germylations, and stannylations are developed. Simply combining toluenes, LiN(SiMe)/CsCl, and RMCl (M = Si, Ge, Sn) generates a diverse array of bench-stable benzyl silanes, germanes, and stannanes (38 examples, 53-90% yields).

Design, Synthesis, and Herbicidal Activity of Naphthalimide-Aroyl Hybrids as Potent Transketolase Inhibitors.

Transketolase (TK) was identified as a new target for the development of novel herbicides. In this study, a series of naphthalimide-aroyl hybrids were designed and prepared based on TK as a new target and tested for their herbicidal activities. In vitro bioassay showed that compounds and exhibited stronger inhibitory effects against () and () with the inhibition over 90% at 200 mg/L and around 80% at 100 mg/L.

Nickel/Photoredox-Catalyzed Enantioselective Reductive Cross-Coupling between Vinyl Bromides and Benzyl Chlorides.

A visible-light-promoted nickel/photoredox-catalyzed reductive cross-coupling reaction between vinyl bromides and benzyl chlorides is reported. A diverse array of enantioenriched allylic centers containing products could be achieved in good yields (up to 90%) and high enantioselectivities (up to 95% ee). The mechanistic studies show that this reductive cross-coupling involves a radical pathway.

2-Arylindoles: Concise Syntheses and a Privileged Scaffold for Fungicide Discovery.

Indole is a popular and functional scaffold existing widely in the fields of medicine, pesticides, spices, food and feed additives, dyes, and many others. Among indoles, 2-arylindole represents a particular and interesting subset but has attracted less attention for drug discovery. In this study, we report a general, practical one-pot assembly of a variety of 2-arylindole derivatives.

Nickel-Catalyzed Reductive Coupling of γ-Metalated Ketones with Unactivated Alkyl Bromides.

A nickel-catalyzed reductive cross-coupling reaction of aryl cyclopropyl ketones with easily accessible unactivated alkyl bromides to access aryl alkyl ketones has been developed. This strategy facilitates access to various of γ-alkyl-substituted ketones via ring opening of cyclopropyl ketones (26 examples, 50-90% yield). Initial mechanistic studies revealed that the reaction proceeds via radical cleavage of the alkyl bromide.

Design, Synthesis, Herbicidal Activity, and Molecular Docking Study of 2-Thioether-5-(Thienyl/Pyridyl)-1,3,4-Oxadiazoles as Potent Transketolase Inhibitors.

Transketolase (TK) has been regarded as a new target for the development of novel herbicides. In this study, a series of 2-thioether-5-(thienyl/pyridyl)-1,3,4-oxadiazoles were designed and synthesized based on TK as the new target. The preliminary bioassay results indicated that compounds and displayed the best herbicidal activities against () and (), with the inhibition exceeding 90% at 100-200 mg/L .

Benzylic Aroylation of Toluenes Mediated by a LiN(SiMe)/Cs System.

Chemoselective deprotonative functionalization of benzylic C-H bonds is challenging, because the arene ring contains multiple aromatic C(sp)-H bonds, which can be competitively deprotonated and lead to selectivity issues. Recently it was found that bimetallic [MN(SiMe) M = Li, Na]/Cs combinations exhibit excellent benzylic selectivity. Herein, is reported the first deprotonative addition of toluenes to Weinreb amides mediated by LiN(SiMe)/CsF for the synthesis of a diverse array of 2-arylacetophenones.

Catalytic enantioselective reductive domino alkyl arylation of acrylates via nickel/photoredox catalysis.

Nonsteroidal anti-inflammatory drug derivatives (NSAIDs) are an important class of medications. Here we show a visible-light-promoted photoredox/nickel catalyzed approach to construct enantioenriched NSAIDs via a three-component alkyl arylation of acrylates. This reductive cross-electrophile coupling avoids preformed organometallic reagents and replaces stoichiometric metal reductants by an organic reductant (Hantzsch ester).

Design, Synthesis, and Herbicidal Activity of Thioether Containing 1,2,4-Triazole Schiff Bases as Transketolase Inhibitors.

Transketolase (TK) represents a potential target for novel herbicide development. To discover novel TK inhibitors with potency against resistant weeds, 36 thioether compounds containing 1,2,4-triazole Schiff bases were designed and synthesized for herbicidal activity evaluation. The results demonstrated that compounds and provided excellent weed control with inhibition of over 90% against the tested weeds, even at concentrations as low as 100 mg/L .

One-Pot Synthesis of N-H-Free Pyrroles from Aldehydes and Alkynes.

The first base-mediated intermolecular cyclization of arylaldehydes and terminal arylacetylenes for the synthesis of a wide range of pyrroles in a single step has been described. The developed methodology used commercially available starting materials and tolerated a broad range of functional groups affording 2,3,5-triaryl-substituted-1-pyrroles with good yields (up to 92% yield) under mild conditions. The possible mechanism was also discussed.

Palladium-Catalyzed Direct Arylation of 2-Pyridylmethyl Silanes with Aryl Bromides.

The first palladium-catalyzed direct arylation of 2-pyridylmethyl silanes with aryl bromides to generate a diverse array of aryl(2-pyridyl)-methyl silane derivatives has been developed. This protocol facilitates access to various kinds of heterocycle-containing silanes in good to excellent yields (40 examples, 66-97% yield) with good functional group tolerance. The scalability of this transformation is demonstrated.