Remote control: The title reaction for β–ζ arylation of α-amino esters with aryl bromides is described. This reaction, which occurs selectively at the terminal position linear alkyl chains, gives rise to synthetically useful (hetero)arylalanines and homologues after debenzylation (see scheme).

We report a general palladium-catalyzed β-arylation of Boc-piperidines, which yields variety valuable 3-arylpiperidines in simple and direct manner. The β- vs. α-arylation selectivity was controlled by the ligand, with flexible biarylphosphines providing mainly desired β-arylated products whereas more rigid furnished classical α-arylated products. computed reaction mechanism (DFT), studied from common α-palladated intermediate, indicated that reductive elimination steps leading to α- are...

New binepine ligands have been synthesized, and characterized shown to induce high diastereo- enantioselectivity in the intramolecular arylation of primary secondary C(sp3)–H bonds, giving rise fused cyclopentanes. The were obtained as bench-stable phosphonium tetrafluoroborate salts that can be directly employed catalysis. It was a ferrocenyl P-substituent on ligand allows achievement stereoselectivities combination with potassium carbonate for C–H bonds under unprecedentedly low...

Abstract The palladium‐catalyzed β‐arylation of ester enolates with aryl bromides was studied both experimentally and computationally. First, the effect ligand on selectivity α/β‐arylation reactions ortho ‐ meta ‐fluorobromobenzene described. Selective observed for reaction o a range biarylphosphine ligands, whereas α‐arylation predominantly m all ligands except DavePhos, which gave an approximate 1:1 mixture α‐/β‐arylated products. Next, substitution pattern bromide reactant DavePhos as...

Abstract The palladium‐catalyzed ligand‐controlled arylation of α‐zincated acyclic amines, obtained by directed α‐lithiation and transmetalation, is described. Whereas P t Bu 3 gave rise to α‐arylated Boc‐protected more flexible N ‐phenylazole‐based phosphine ligands induced major β‐arylation through migrative cross‐coupling.

A new class of strigolactone analogues has been synthesized. They differ from known molecules, both natural and synthetic origin, in two main features. The conjugated system extends the enol ether bridge to ring, B ring is a heterocycle while C cyclic ketone instead γ-lactone. key step synthesis Nazarov cyclization on activated substrates. Bioassays using Orobanche seeds have revealed that all molecules strongly stimulate germination; particular oxygen containing are most active....

Fernsteuerung: Die Titelreaktion ermöglicht die β- bis ζ-Arylierung von α-Aminosäureestern mit Arylbromiden. Reaktion findet selektiv an der endständigen Position linearen Alkylkette statt und liefert nach Debenzylierung präparativ nützliche (Hetero)arylalanine (siehe Schema). Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted by the authors. Please note: The...

Molecular materials that possess a toroidal moment associated to non-magnetic ground state are known as single-molecule toroics (SMTs) and usually planar molecules. Herein, we report Dy4 cubane, namely [Dy4 (Bppd)4 (μ3 -OH)4 (Pa)4 (H2 O)4 ]⋅0.333 H2 O (where BppdH=1,3-Bis(pyridin-4-yl)propane-1,3-dione PaH=2-Picolinic acid) for which magnetometry measurements state-of-art ab initio calculations highlight SMT behavior in tridimensional structure (3D-SMT). The in-depth theoretical analysis on...

Ethylene/butadiene copolymerization can be performed by neodymocene catalysts in the presence of an alkylating/chain transfer agent. A variety polymerization activities and copolymer microstructures obtained depending on ligands. For a set four catalysts, namely (C5Me5)2NdR, [Me2Si(3-Me3SiC5H3)2]NdR, [Me2Si(C5H4)(C13H8)]NdR [Me2Si(C13H8)2]NdR, we report DFT mechanistic study this reaction dialkylmagnesium. Based modeling strategy developed for ethylene homopolymerization catalyzed...

Abstract The one‐step polycondensation of diamines and diboranes triggered by the in situ deprotonation diammonium salts concomitant reduction bisboronic acids leads to assembly polymer chains through multiple Lewis pairing their backbone. These new polyboramines are dihydrogen reservoirs that can be used for hydrogenation imines carbonyl compounds. They also display a unique thermal release profile is direct consequence insertion amine–borane linkages polymeric

Silyl ketene acetals are shown to be competent nucleophiles in Pd-catalyzed migrative C(sp3)–H arylations. Compared the parent ester lithium enolates, they possess decreased reactivity but enhanced chemoselectivity. This behavior was exploited through synthesis of valuable benzo-fused δ-lactones such as 1-isochromanones and dihydrocoumarins.

[reaction: see text] A highly efficient carbonylative Suzuki-Miyaura coupling reaction of lactam-derived vinyl triflates and alkenylboronic acids afforded 2-(N-methoxycarbonylamino)-1,4-pentadien-3-ones as suitable substrates for the Nazarov reaction. The most competent Lewis were Cu(OTf)(2) (2 mol %) Sc(OTf)(3) (3 in DCE, which provided products excellent yield. As both subsequent high yielding, overall methodology is a concise route to [1]pyrindine systems.

The direct transformation of lactam-, lactone-, and thiolactone-derived triflates into N-methoxy-N-methyl or morpholine Weinreb amides has been realized using Pd-catalyzed aminocarbonylation under CO atmospheric pressure at room temperature. carbonylative coupling can be efficiently carried out with 2% catalyst in the presence Xantphos as a ligand. smoothly react nucleophiles to afford acylated aza-, oxa-, thio-heterocycles. proposed methodology could advantageously exploited for synthesis...

An optimized ligand-controlled palladium-catalyzed allene synthesis starting from alkynes and aryl bromides giving rise to products in a simple direct manner is described. The methodology performed an inter- intramolecular fashion with unprecedented scope excellent yields. Based on mechanistic investigations DFT calculations, the role played by carboxylic additive (i.e., PivOH) controlling selectivity of reaction discussed, allowing us propose base-assisted deprotonation (iBAD) mechanism for...

Abstract A thorough study of the carbonylative Suzuki–Miyaura cross‐coupling reaction enol triflates with alkenylboronic acids for synthesis unsymmetrical dienones is reported. Conditions were found that enabled coupling structurally different derived from lactams, lactones, and thiolactones (i.e., cyclic ketene aminal, acetal, thioacetal triflates, respectively) various at room temperature under 1 atm CO pressure 1–5 % palladium catalyst; carbonylated products obtained in 50–86 overall...

Abstract The high‐yielding synthesis of 5‐bromopenta‐2,4‐diynenitrile (BrC 5 N) was achieved for the first time. Its reactivity with triisopropylsilylacetylene and triisopropylsilylbutadiyne in presence copper palladium as co‐catalysts diisopropylamine evaluated. It revealed an unprecedented cascade reaction leading to a diene one case benzofulvene other case, unique structure. Both them were characterized by X‐ray crystallography, among techniques. mechanism investigated experimentally....

Abstract The palladium‐catalyzed ligand‐controlled arylation of α‐zincated acyclic amines, obtained by directed α‐lithiation and transmetalation, is described. Whereas P t Bu 3 gave rise to α‐arylated Boc‐protected more flexible N ‐phenylazole‐based phosphine ligands induced major β‐arylation through migrative cross‐coupling.

o-Benzenedisulfonimide has been used for the first time as a Brønsted acid catalyst to induce electrocyclization of dienones into cyclopentenones (Nazarov reaction). The in various organic solvents or under solvent-free conditions and it is entirely recoverable from reaction mixture. versatility effectiveness proposed procedure demonstrated on wide range both activated inactivated substrates.

We report a ligand-free green synthesis of arylthiophenes and poly(3-hexyl)thiophene in GVL under microwave irradiation.

4-Aminoquinolines were prepared in a three-step synthesis starting from substituted anthranilonitriles. The condensation on 1,1,1-trichloro-4-ethoxybut-3-enone proceeded efficiently either neat or refluxing EtOH. Cyclization superacidic trifluoromethanesulfonic acid provided unstable intermediate, which upon treatment with NaOEt ethanol, afforded the expected esters. Theoretical investigations pointed out monoprotonated nitrilium as reactive species during cyclization process.

Abstract The one‐step polycondensation of diamines and diboranes triggered by the in situ deprotonation diammonium salts concomitant reduction bisboronic acids leads to assembly polymer chains through multiple Lewis pairing their backbone. These new polyboramines are dihydrogen reservoirs that can be used for hydrogenation imines carbonyl compounds. They also display a unique thermal release profile is direct consequence insertion amine–borane linkages polymeric

A new family of three Dy III mononuclear complexes and one chain system based on the same ligand [1,3‐di(pyridin‐4‐yl)propane‐1,3‐dione] has been isolated as single crystals. By varying synthesis conditions, it possible to finely control number ligands coordinated central lanthanide atom (from 1 3) then total charge complex unit +2 neutral), well local geometry around ion D 4 d 2 ). The magnetic properties four have studied rationalized by ab initio calculations illustrate correlation...

Abstract Molecular materials that possess a toroidal moment associated to non‐magnetic ground state are known as single‐molecule toroics (SMTs) and usually planar molecules. Herein, we report Dy 4 cubane, namely [Dy (Bppd) (μ 3 ‐OH) (Pa) (H 2 O) ]⋅0.333 H O (where BppdH=1,3‐Bis(pyridin‐4‐yl)propane‐1,3‐dione PaH=2‐Picolinic acid) for which magnetometry measurements state‐of‐art ab initio calculations highlight SMT behavior in tridimensional structure (3D‐SMT). The in‐depth theoretical...

Spiro-glyco-heterocycles were prepared on a gram scale from thiolactone obtained by thermolysis of thiosulfinate. Lowering glycaemia in diabetic rat models is pointing toward potential new treatment type 2 diabetes.

The substitution of biarylphosphine ligands was shown to have a marked impact on the α/β selectivity arylation ester enolates. To get further insight into this effect, solid-state structures arylpalladium bromide and malonate complexes with four different were obtained by X-ray diffraction analysis. Structural differences not very pronounced except for conformationally restricted CPhos ligand, which showed bidentate coordination mode in oxidative addition complex, whereas other form dimeric species.