Tag: M.W=400-450

King, Ryan P. published the artcileA Ligand Exchange Process for the Diversification of Palladium Oxidative Addition Complexes, Safety of 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, the publication is Organic Letters (2021), 23(15), 6030-6034, database is CAplus and MEDLINE.

Palladium oxidative addition complexes (OACs) have recently emerged as useful tools to enable challenging bond connections. However, each OAC can only be formed with one dative ligand at a time. As no one ligand is optimal for every cross-coupling reaction, we herein disclose a ligand exchange protocol for the preparation of a series of OACs bearing a variety of ancillary ligands from one common complex. These complexes were further applied to cross-coupling transformations.

Organic Letters published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C28H41N2P, Safety of 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

King, Ryan P. published the artcileA Neophyl Palladacycle as an Air- and Thermally Stable Precursor to Oxidative Addition Complexes, COA of Formula: C28H41N2P, the publication is Organic Letters (2021), 23(20), 7927-7932, database is CAplus and MEDLINE.

The use of isolated Pd Oxidative Addition Complexes (OACs) has had a significant impact on Pd-catalyzed and Pd-mediated cross-coupling reactions. Despite their importance, widespread utility of OACs was limited by the instability of their precursor complexes. Herein, the authors report the use of Campora’s palladacycle as a new, more stable precursor to Pd OACs. Using this palladacycle, biarylphosphine ligated OACs, including those with pharmaceutical-derived aryl halides and relevance to bioconjugation, were prepared

Organic Letters published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C28H41N2P, COA of Formula: C28H41N2P.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Larini, Paolo published the artcileOn the Mechanism of the Palladium-Catalyzed β-Arylation of Ester Enolates, Recommanded Product: 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, the publication is Chemistry – A European Journal (2012), 18(7), 1932-1944, S1932/1-S1932/163, database is CAplus and MEDLINE.

The palladium-catalyzed β-arylation of ester enolates with aryl bromides was studied both exptl. and computationally. First, the effect of the ligand on the selectivity of the α/β-arylation reactions of ortho- and meta-fluorobromobenzene was described. Selective β-arylation was observed for the reaction of o-fluorobromobenzene with a range of biarylphosphine ligands, whereas α-arylation was predominantly observed with m-fluorobromobenzene for all ligands except DavePhos, which gave an approx. 1:1 mixture of α-/β-arylated products. Next, the effect of the substitution pattern of the aryl bromide reactant was studied with DavePhos as the ligand. We showed that electronic factors played a major role in the α/β-arylation selectivity, with electron-withdrawing substituents favoring β-arylation. Kinetic and deuterium-labeling experiments suggested that the rate-limiting step of β-arylation with DavePhos as the ligand was the palladium-enolate-to-homoenolate isomerization, which occurs by a βH-elimination, olefin-rotation, and olefin-insertion sequence. A dimeric oxidative-addition complex, which was shown to be catalytically competent, was isolated and structurally characterized. A common mechanism for α- and β-arylation was described by DFT calculations With DavePhos as the ligand, the pathway leading to β-arylation was kinetically favored over the pathway leading to α-arylation, with the palladium-enolate-to-homoenolate isomerization being the rate-limiting step of the β-arylation pathway and the transition state for olefin insertion its highest point. The nature of the rate-limiting step changed with PCy₃ and PtBu₃ ligands, and with the latter, α-arylation became kinetically favored. The trend in selectivity observed exptl. with differently substituted aryl bromides agreed well with that observed from the calculations The presence of electron-withdrawing groups on these bromides mainly affected the α-arylation pathway by disfavoring CC reductive elimination. The higher activity of the ligands of the biaryldialkylphosphine ligands compared to their corresponding trialkylphosphines could be attributed to stabilizing interactions between the biaryl backbone of the ligands and the metal center, thereby preventing deactivation of the β-arylation pathway.

Chemistry – A European Journal published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C28H41N2P, Recommanded Product: 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Wezeman, Tim published the artcileSynthesis of Non-Symmetrical and Atropisomeric Dibenzo[1,3]diazepines: Pd/CPhos-Catalyzed Direct Arylation of Bis-Aryl Aminals, Related Products of quinuclidine, the publication is Australian Journal of Chemistry (2015), 68(12), 1859-1865, database is CAplus.

Pd/CPhos-catalysis provides direct arylation/cyclization of methylene-linked bis[anilines] to dibenzo[1,3]diazepines which are both non-(C2)-sym. and axially chiral. Synthesis of the direct arylation substrates commences with substitution of (N-acyl)anilines to methylene Me sulfide derivatives, followed by halogenation/de-thiomethylation to N-(chloromethyl)anilines. These are substituted with a second aniline derivative, allowing modular preparation of (ortho-halo)aryl-aminal-linked arenes. The C-H functionalizing direct arylation conditions were adapted from Fagnou and others: substrates and potassium carbonate were heated in dimethylacetamide in the presence of palladium acetate and an electron-rich and sterically hindered biarylphosphine ligand, here CPhos. These conditions delivered the C1-(a)sym. dibenzo[1,3]diazepine targets, which, due to torsion around the axis of the newly formed biaryl bond, are also intrinsically atropisomeric. The axially twisted scaffold is known to impart special properties to ligands/catalysts when the products are further converted into the corresponding seven-membered ring-containing N-heterocyclic carbenes. Under optimized conditions the synthesis of the target compounds was achieved using 2′-(dicyclohexylphosphino)-N²,N²,N⁶,N⁶-tetramethyl[1,1′-biphenyl]-2,6-diamine (i.e., CPhos) and palladium acetate as ligand and catalyst combination. Key intermediates included N,N’-(methylene)-N,N’-bis(phenyl)acetamide derivatives (i.e., the above-mentioned aminals).

Australian Journal of Chemistry published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C5H12O2, Related Products of quinuclidine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Kang, Houng published the artcileEnantioselective Vanadium-Catalyzed Oxidative Coupling: Development and Mechanistic Insights, Formula: C28H41N2P, the publication is Journal of Organic Chemistry (2018), 83(23), 14362-14384, database is CAplus and MEDLINE.

The evolution of a more reactive chiral vanadium catalyst for enantioselective oxidative coupling of phenols is reported, ultimately resulting in a simple monomeric vanadium species combined with a Bronsted or Lewis acid additive. The resultant vanadium complex is found to effect the asym. oxidative ortho-ortho coupling of simple phenols and 2-hydroxycarbazoles with good to excellent levels of enantioselectivity. Exptl. and quantum mech. studies of the mechanism indicate that the additives aggregate the vanadium monomers. In addition, a singlet to triplet crossover is implicated prior to carbon-carbon bond formation. The two lowest energy diastereomeric transition states leading to the enantiomeric products differ substantially with the path to the minor enantiomer involving greater torsional strain between the two phenol moieties.

Journal of Organic Chemistry published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C28H41N2P, Formula: C28H41N2P.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Probst, Nicolas published the artcileIntramolecular Pd-Catalyzed Anomeric C(sp³)-H Activation of Glycosyl Carboxamides, Related Products of quinuclidine, the publication is Organic Letters (2017), 19(19), 5038-5041, database is CAplus and MEDLINE.

An expedient method for the synthesis of fused glycosylquinolin-2-ones and glycosylspirooxindoles through an unprecedented intramol. Pd-catalyzed anomeric C-H activation of the sugar moiety of 2-bromophenyl glycosylcarboxamides is reported. The scope of the reaction is broad and tolerates a wide range of functional groups.

Organic Letters published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C28H41N2P, Related Products of quinuclidine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Coombs, John R. published the artcileAdvances in Base-Metal Catalysis: Development of a Screening Platform for Nickel-Catalyzed Borylations of Aryl (Pseudo)halides with B₂(OH)₄, Safety of 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, the publication is Organometallics (2019), 38(1), 157-166, database is CAplus.

Investigations into nickel-catalyzed borylation reactions have led to the development of an exptl. design of 24 reaction conditions for rapid lead identification. A case study on the borylation of a model aryl bromide with B₂(OH)₄ prompted a series of mechanistic and stability studies to better understand the catalytic cycle and factors that affect robustness. HTEx was employed to study the effect of a series of scavengers on the remediation of nickel from the reaction stream. These combined results have generated an increased understanding of nickel-catalyzed borylation reactions and set the stage for their expanded use in process chem.

Organometallics published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C28H41N2P, Safety of 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Hornillos, Valentin published the artcileDirect catalytic cross-coupling of alkenyllithium compounds, Related Products of quinuclidine, the publication is Chemical Science (2015), 6(2), 1394-1398, database is CAplus and MEDLINE.

A catalytic method for the direct cross-coupling of alkenyllithium reagents with aryl and alkenyl halides is described. The use of a catalyst comprising Pd₂(dba)₃/XPhos allows for the stereoselective preparation of a wide variety of substituted alkenes in high yields under mild conditions. In addition (1-ethoxyvinyl)lithium can be efficiently converted into substituted vinyl ethers which, after hydrolysis, give readily access to the corresponding Me ketones in a one pot procedure.

Chemical Science published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C28H41N2P, Related Products of quinuclidine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Fornwald, Ryan M. published the artcileInfluence of Catalyst Structure and Reaction Conditions on anti- versus syn-Aminopalladation Pathways in Pd-Catalyzed Alkene Carboamination Reactions of N-Allylsulfamides, Recommanded Product: 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, the publication is Chemistry – A European Journal (2014), 20(28), 8782-8790, database is CAplus and MEDLINE.

The Pd-catalyzed coupling of N-allylsulfamides with aryl and alkenyl triflates to afford cyclic sulfamide products is described. In contrast to other known Pd-catalyzed alkene carboamination reactions, these transformations may be selectively induced to occur by way of either anti- or syn-aminopalladation mechanistic pathways by modifying the catalyst structure and reaction conditions.

Chemistry – A European Journal published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C28H41N2P, Recommanded Product: 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Li, Houhua published the artcileExploring Site Selectivity of Iridium Hydride Insertion into Allylic Alcohols: Serendipitous Discovery and Comparative Study of Organic and Organometallic Catalysts for the Vinylogous Peterson Elimination, SDS of cas: 1160556-64-8, the publication is ACS Catalysis (2017), 7(3), 1554-1562, database is CAplus.

The vinylogous Peterson elimination of a broad range of primary, secondary, and tertiary silylated allylic alcs. by two distinct and complementary catalytic systems – a cationic iridium complex and a Bronsted acid – is reported. These results are unexpected. Nonsilylated substrates are typically isomerized into aldehydes and silylated allylic alcs. into homoallylic alcs. with structurally related iridium complexes. Although several organic acids and bases are known to promote the vinylogous Peterson elimination, the practicality, mildness, functional group tolerance, and generality of both catalysts are simply unprecedented. Highly substituted C=C bonds, stereochem. complex scaffolds, and vicinal tertiary and quaternary (stereo)centers are also compatible with the two methods. Both systems are stereospecific and enantiospecific. After optimization, a vast number of dienes with substitution patterns that would be difficult to generate by established strategies are readily accessible. Importantly, control experiments secured that traces of acid that may be generated upon decomposition of the in situ generated iridium hydride are not responsible for the activity observed with the organometallic species. Upon inspection of the reaction scope and on the basis of preliminary investigations, a mechanism involving iridium-hydride and iridium-allyl intermediates is proposed to account for the elimination reaction. Overall, this study confirms that site selectivity for [Ir-H] insertion across the C=C bond of allylic alcs. is a key parameter for the reaction outcome.

ACS Catalysis published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C28H41N2P, SDS of cas: 1160556-64-8.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider