Abstract
γ-Amino acids and peptides analogues are common constituents of building blocks for numerous biologically active molecules, pharmaceuticals, and natural products. In particular, γ-amino ...acids are providing with better metabolic stability than α-amino acids. Herein we report a multicomponent carbonylation technology that combines readily available amides, alkenes, and the feedstock gas carbon monoxide to build architecturally complex and functionally diverse γ-amino acid derivatives in a single step by the implementation of radical relay catalysis. This transformation can also be used as a late-stage functionalization strategy to deliver complex, advanced γ-amino acid products for pharmaceutical and other areas.
The synthetic utilities of acylgermanes are surprisingly rarely explored compared with their analogues. In this communication, the survey of aroyltrimethylgermane as potent synthetic origins has been ...studied. A variety of novel chemical transformations have been realized, including using the acylgermane group as a directing group in Rh-catalyzed aromatic C-H alkenylation reaction and Ir-catalyzed aromatic C-H amidation reactions. Additionally, a general approach for acylgermanes preparation has been established as well. The catalytic system proceeds effectively in the presence of Pd(OAc)2/BINOL-based monophosphite (L11) and allows for the straightforward access to a wide range of functionalized acylgermanes in high yields.
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•The first carbonylation procedure for acylgermanes synthesis has been established•Synthetic transformations of acylgermanes have been developed•New BINOL-based monophosphite ligand is designed and applied
Catalysis; Organic Synthesis; Organic Reaction; Chemical Synthesis
Abstract This study examined whether very early initiated physical rehabilitation (VEIPR), as a recommended therapy for postischemia, could improve motor performance and cerebral blood flow (CBF). ...Adult male rats with ischemic injury caused by middle cerebral artery occlusion (MCAO) were trained to run on a treadmill for 30 min per day at 12 m/min. Through such exercise training for 3 days, the ischemic rats exhibited increased motor function and decreased infarct volume, as measured by a behavioral score and 2,3,5-triphenyltetrazolium chloride (TTC) staining method, as well as accelerated CBF, as detected with laser speckle imaging (LSI). Furthermore, to determine whether the observed improved CBF provided the protective factor for motor function recovery, we investigated the apoptosis of ischemic rat brain microvascular endothelial cells (rBMECs), which accepted the mechanical force of CBF directly, under flow intervention. The findings indicated that a modest flow decreased cell apoptosis in the ischemic condition and that this effect is magnitude dependent, as excessive flow increased apoptosis.
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•A novel palladium-catalyzed four-component difluoroalkylative carbonylation of styrenes.•Multicomponent difluoroalkylative carbonylation of activated aryl olefins and ...ethylene.•Various desired products were produced in moderate to excellent yields with wide functional group tolerance and excellent regioselectivity.•The first successful example on using styrenes as substrates in fluoroalkylative aminocarbonylation.
Compared with unactivated alkyl olefins, the corresponding fluorinative carbonylation of styrenes has remained a challenge due to its strong tendency for oligomerization and polymerization. In this communication, we developed a palladium-catalyzed four-component difluoroalkylative carbonylation of aryl olefins for the first time. A wide range of β-difluoromethylene substituted amide derivatives were prepared in moderate to high yields with excellent regioselectivity. Notably, ethylene gas, as an original C2 synthon, can also be transformed to the corresponding products with moderate yields. Furthermore, some natural product or bio-active molecule related compounds, such as estrogen, benzocaine, and menthol derivatives can be reacted as well. This reaction can be scaled up smoothly and the obtained product can be further transformed into amidic acid and aminol efficiently.
We have developed a photoinducted Cu/BINAP-catalyzed multicomponent perfluoroalkylation and carbonylation tandem sequence of unactivated alkenes with perfluoroalkyl halides, CO, and different ...nucleophiles. Under mild reaction conditions, various functionalized β-perfluoroalkyl carbonyl compounds were produced from inexpensive and readily available starting materials in moderate to excellent yields with broad functional group tolerance and excellent chemo- and regioselectivity.
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•A photoinducted carbonylation.•Multicomponent perfluoroalkylative carbonylation of unactivated alkenes.•Various functionalized β-perfluoroalkyl carbonyl compounds were produced in moderate to excellent yields.•Broad functional group tolerance and excellent chemo- and regioselectivity.•Cu/BINAP as the photosensor and catalyst.
Employing a photocatalyst system based on copper and BINAP, visible light-mediated perfluoroalkylative carbonylation of unactivated alkenes has been developed. The method enables a photo-promoted perfluoroalkyl radical addition-carbon monoxide insertion-coupling cascade approach to functionalized β-perfluoroalkyl carbonyl compounds. Various substrates, including alkenes, perfluoroalkyl halides, and nucleophiles (including phenols, alcohols, and amines) are suitable for this tandem procedure, providing more than 70 examples of valuable β-perfluoroalkyl esters and amides with good functional-group tolerance and excellent chemo- and regioselectivity. In addition, late-stage perfluoroalkylative carbonylation of several pharmaceutical and bioactive molecules has been successfully achieved as well.
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•Copper-catalyzed carbonylative transformation of N-fluoro-sulfonamides.•Novel procedure for δ-lactams and esters involving 1,5-hydrogen atom transfer.•Modification of medicine ...Celecoxib-derived substrate.
Herein, we developed an interesting copper-catalyzed carbonylation approach for the transformations of the remote C(sp3)H bonds in N-fluoro-sulfonamides. The corresponding δ-lactams and esters were produced selectively. Notably, N-fluoro-carboxamide and medicine Celecoxib-derived substrate can also be transformed under the same conditions.
Transition‐metal‐catalyzed multi‐component carbonylation represents an efficient strategy for the preparation of various functionalized carbonyl‐containing compounds. Herein, we report a general ...palladium‐catalyzed perfluoroalkylative carbonylation of unactivated alkenes using inexpensive and readily available carbon monoxide as the C1 source and perfluoroalkyl halides as the coupling partner. A wide range of phenols and alcohols were transformed into the corresponding β‐perfluoroalkyl esters in high yields with broad functional group tolerance and good chemoselectivity. Additionally, alkyl halides can be utilized as alkoxy source as well to give the desired esters. Moreover, several pharmaceutical and bio‐active molecules were also suitable substrates for this one‐pot multi‐component carbonylation process to give the targeted products in good yields.
An efficient and convenient palladium‐catalyzed perfluoroalkylative carbonylation of unactivated alkenes has been developed. More than 100 examples of β‐perfluoroalkyl esters were prepared directly from readily available substrates with good functional group tolerance and chemoselectivity.
Herein, we developed a copper‐catalyzed approach for the remote C(sp3)−H alkynylation of N‐fluoro‐sulfonamides. With Cu(OTf)2 as the catalyst, the carbon radical which generated from nitrogen ...radical‐mediated 1,5‐hydrogen atom transfer, go through an addition/fragmentation reaction with various acetylene sulfones. A variety of internal alkynes were synthesized in high yield and regioselectivity. Notably, celecoxib‐derived substrate can also gave the corresponding functionalized product in good yield under the standard conditions.
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•A novel copper/visible light catalyzed ring-opening carbonylation of sulfonium salts.•A direct and effective strategy for the synthesis of sulfur-containing carboxylic acid ...derivatives.•A variety of substrates were successfully transformed into the desired carbonylated products in moderate to good yields with good functional group tolerance and excellent chemoselectivity.
Herein, we developed a direct and effective strategy for the synthesis of sulfur-containing carboxylic acid derivatives through copper/visible light catalyzed ring-opening carbonylation of sulfonium salts. The protocol employs photoredox to promote the selective cleavage of sulfonium salts C(sp3)-S bond, while performing sequential functionalization to form vicinal C–C and C-X (X = O or N) bonds in the presence of carbon monoxide and nucleophiles. A variety of substrates were successfully transformed into the desired carbonylated products in moderate to good yields with good functional group tolerance and excellent chemoselectivity. Importantly, this approach can be easily extended to late-stage modification of bioactive molecules.
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