Bridging 1,2-Bis(diphenylphosphino)methane Ligands Facilitate the Formation of Binuclear Complexes with Both Two-Coordinate and Three-Coordinate Gold(I) Ions.

Five new crystalline gold(I) complexes β-Au(μ-dppm)Br·2CHCl (), [Au(μ- dppm)Br]Br·2CHCl (), [Au(μ-dppm)Br](PF) (), [Au(μ-dppm)Cl](BPh)·3CHCl () and [Au(μ-dppm)]Cl(AsF)·2CHCl () (where dppm is bis(diphenylphosphino)methane) have been prepared and structurally characterized by single crystal X-ray diffraction. Colorless β-Au(μ-dppm)Br·2CHCl () has centrosymmetric structure with two three-coordinate gold(I) ions held in close proximity by the dppm ligands. Crystals of [Au(μ- dppm)Br]Br·2CHCl (), [Au(μ-dppm)Br](PF) (), and [Au(μ-dppm)Cl](BPh)·3CHCl () have a cation with an unusual arrangement that binds a two-coordinate gold(I) ion to a three-coordinate gold(I) ion through an aurophilic interaction.

Assembly of the Tricyclic Core of Alopecurone C by Asymmetric Donor/Donor Carbene C-H Insertion.

Two routes to assemble the complete tricyclic core of alopecurone C are described. In the first-generation route, an efficient synthesis of the "eastern" half of the target, including a decagram-scale rhodium-catalyzed C-H insertion reaction, was developed. When this route proved intractable for assembling the final flavanone ring, a successful second-generation route was developed from a flavanone precursor (naringenin) employing a later stage C-H insertion.

Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF- and CFSF-containing [2]staffanes.

Selectivity in radical chain oligomerizations involving [1.1.1]propellane - i.

Correction: Catalytic generation of -quinone dimethides donor/donor rhodium carbenes.

[This corrects the article DOI: 10.1039/D3SC00734K.].

Molecular Flexibility in Solvated Crystals of the Dimer, Au(μ-1,2-bis(diphenylphosphino)ethane)I, with Three-Coordinate Gold(I).

We report the ability to trap the dimer Au(μ-dppe)I (dppe is 1,2-bis(diphenylphosphino)ethane) with different separations between the three-coordinate gold ions in crystalline solvates. All of these solvates ((Au(μ-dppe)I·4(CHCl) (), Au(μ-dppe)I·2(CHCl) (), the polymorphs α-Au(μ-dppe)I·2(HC(O)NMe) () and β-Au(μ-dppe)I·2(HC(O)NMe) (), and Au(μ-dppe)I·4(CHCl) ()) along with polymeric {Au(μ-dppe)I}·(CHCl) ()) originated from the same reaction, only the solvent system used for crystallization differed. In the different solvates of Au(μ-dppe)I, the Au···Au separation varied from 3.

Desymmetrization of Cyclic Sulfonimidamides by Asymmetric Allylation.

Herein we report the first transition metal-catalyzed approach to the enantioenriched synthesis of cyclic sulfonimidamides relying on commercially available palladium catalysts and ligands. High-throughput experimentation (HTE) was employed to identify the optimal catalyst system and solvent. The method is applied to a variety of saturated and unsaturated rings and exhibits the highest selectivity for 2-substituted allyl electrophiles.

Organocatalytic Asymmetric Synthesis of Si-Stereogenic Siloxanols.

We report the organocatalytic synthesis of Si-stereogenic compounds via desymmetrization of a prochiral silanediol with a chiral imidazole-containing catalyst. This metal-free silylation method affords high yields with enantioselectivity up to 98:2 for various silanediol and silyl chloride substrate combinations (including secondary alkyl, vinyl, and H groups), accessing products with potential for further elaboration. NMR and X-ray studies reveal insight into the H-bonding interactions between the imidazole organocatalyst and the silanediol and the dual activating role of the Lewis basic imidazole to account for the high enantioselectivity.

Overcoming a Radical Polarity Mismatch in Strain-Release Pentafluorosulfanylation of [1.1.0]Bicyclobutanes: An Entryway to Sulfone- and Carbonyl-Containing SF-Cyclobutanes.

The first assortment of achiral pentafluorosulfanylated cyclobutanes (SF-CBs) are now synthetically accessible through strain-release functionalization of [1.1.0]bicyclobutanes (BCBs) using SFCl.

Deconvoluting Nonlinear Catalyst-Substrate Effects in the Intramolecular Dirhodium-Catalyzed C-H Insertion of Donor/Donor Carbenes Using Data Science Tools.

Interactions between catalysts and substrates can be highly complex and dynamic, often complicating the development of models to either predict or understand such processes. A dirhodium(II)-catalyzed C-H insertion of donor/donor carbenes into 2-alkoxybenzophenone substrates to form benzodihydrofurans was selected as a model system to explore nonlinear methods to achieve a mechanistic understanding. We found that the application of traditional methods of multivariate linear regression (MLR) correlating DFT-derived descriptors of catalysts and substrates leads to poorly performing models.

Hydrobismuthation: Insertion of Unsaturated Hydrocarbons into the Heaviest Main Group Element Bond to Hydrogen.

The bismuth hydride (2,6-MesHC)BiH (, Mes = 2,4,6-trimethylphenyl), which has a Bi-H H NMR spectroscopic signal at δ = 19.64 ppm, was reacted with phenylacetylene at 60 °C in toluene to yield [(2,6-MesCH)BiC(Ph)=CH] () after 15 min. Compound was characterized by H, C NMR, and UV-vis spectroscopy, single crystal X-ray crystallography, and calculations employing density functional theory.

Group 13 ion coordination to pyridyl breaks the reduction potential hydricity scaling relationship for dihydropyridinates.

The relationship Δ correlates the applied potential () needed to drive organohydride formation with the strength of the hydride donor that is formed: in the absence of kinetic effects Δ should be linear but it would be more energy efficient if could be shifted anodically using kinetic effects. Biological hydride transfers (HT) performed by cofactors including NADH and lactate racemase do occur at low potentials and functional modeling of those processes could lead to low energy HT reactions in electrosynthesis and to accurate models for cofactor chemistry. Herein we probe the influence of -alkylation or -metallation on Δ for dihydropyridinates (DHP) and on of the DHP precursors.

Sn(II)-carbon bond reactivity: radical generation and consumption reactions of a stannylene with alkynes.

Thermal Sn-C cleavage in the diarylstannylene Sn(Ar) (Ar = CH-2,6-(CH-2,6-iPr)) was used to generate ˙Sn(Ar) and ˙Ar radicals for alkyne arylstannylation. The radical pair and RCCR' (R = H, R' = Ph; R = Ph, R' = Ph; R = H, R' = CH; R = H, R' = SiMe) in refluxing benzene generate the aryl vinyl stannylene complexes, ArSn{C(CH)-C(H)(Ar)} (1), ArSn{C(CH)-C(H)(CH)} (2) and ArSn{C(CH)-C(H)(Ar)} (3) respectively. For HCCSiMe, the known distannene {Sn(CCSiMe)Ar} (4) was also generated from this new method.

Structure and Luminescence Studies of Salts of the Helical Dication, [Au(μ-bis(diphenylphosphine)ethane)] and Comparison with Salts of [Au(μ-bis(diphenylphosphine)propane)].

Six salts ([Au(μ-dppe)](BF)·CHCl, [Au(μ-dppe)](BF)·1,2-ClCH, [Au(μ-dppe)](PF)·CHCl, [Au(μ-dppe)](PF), [Au(μ-dppe)](SbF), and [Au(μ-dppe)](OTf)·2CHCl), (dppe is bis(diphenylphosphine)ethane) containing the dication, [Au(μ-dppe)], have been prepared and structurally characterized by single-crystal X-ray crystallography. Unlike the three-coordinate dppe-bridged dimers, AuX(μ-dppe) (X = Br, I), which show considerable variation in the distance between the gold(I) ions over the range 3.0995(10) to 3.

Correction to "Synthesis, Structure, and Spectroscopy of the Biscarboranyl Stannylenes (bc)Sn·THF and K[(bc)Sn] (bc = 1,1'(-Biscarborane)) and Dibiscarboranyl Ethene (bc)CH=CH(bc)".

[This corrects the article DOI: 10.1021/acs.organomet.

Reactions of Thianthrene and 10-Phenylphenothiazine with the Lewis Acids─Titanium Tetrachloride, Titanium Tetrabromide, Tin(IV) Tetrachloride, or Antimony(V) Pentachloride: The Competition between Coordination and Oxidation.

The oxidation of thianthrene and 10-phenylphenothiazine into cation radicals has been examined using redox-active Lewis acids. The reaction of titanium(IV) tetrachloride with thianthrene in toluene produces a solution with an EPR spectrum indicative of oxidation of thianthrene to a cation radical, but the molecular compound () (μ-thianthrene)Ti(μ-Cl)Cl crystallized exclusively. Red crystalline () (μ-thianthrene)Ti(μ-Br)Br formed similarly from titanium(IV) tetrabromide.

Synthesis, Structure, and Spectroscopy of the Biscarboranyl Stannylenes ()Sn·THF and K[()Sn] ( = 1,1'(-Biscarborane)) and Dibiscarboranyl Ethene ()CH=CH().

Two compounds containing a Sn(II) atom supported by a bidentate biscarborane ligand have been synthesized via salt metathesis. The synthetic procedures for ()Sn·THF ( = 1,1' (-carborane) () and K[()Sn] () involved the reaction of K[] with SnCl in either a THF solution () or in a benzene/dichloromethane solvent mixture (). Using the same solvent conditions as those used for but using a shorter reaction time gave a dibiscarboranyl ethene ().

Group 13 ion coordination to pyridyl models NAD reduction potentials.

-alkylation and -metallation of pyridine are explored herein to understand how metal-ligand complexes can model NAD redox chemistry. Syntheses of substituted dipyrazolylpyridine (pzP) compounds (pzP)Me (1) and (pzP)GaCl (2) are reported, and compared with (pzP)AlCl(THF) and transition element pzP complexes from previous reports. Cyclic voltammetry measurements of cationic 1 and 2 show irreversible reduction events ∼900 mV anodic those for neutral pzP complexes of divalent metals.

Rearrangement of a Ge(II) aryloxide to yield a new Ge(II) oxo-cluster [Ge(μ-O)(μ-OCH-2,4,6-Cy)](NH): main group aryloxides of Ge(II), Sn(II), and Pb(II) [M(OCH-2,4,6-Cy)] (Cy = cyclohexyl).

The new Ge(II) cluster [Ge(μ-O)(μ-OCH-2,4,6-Cy)](NH) (1) and three divalent Group 14 aryloxide derivatives [Ge(OCH-2,4,6-Cy)] (2), [Sn(OCH-2,4,6-Cy)] (3), and [Pb(OCH-2,4,6-Cy)] (4) of the new tricyclohexylphenyloxo ligand, [(-OCH-2,4,6-Cy)] (Cy = cyclohexyl), were synthesized and characterized. Complexes 1-4 were obtained by reaction of the metal bissilylamides M(N(SiMe)) (M = Ge, Sn, Pb) with 2,4,6-tricyclohexylphenol in hexane at room temperature. If the freshly generated reaction mixture for the synthesis of 2 is stirred in solution for 12 h at room temperature, the cluster [Ge(μ-O)(μ-OCH-2,4,6-Cy)](NH) (1), which features a rare GeO core that includes ammonia molecules in non-coordinating positions, is formed.

Mn(II), Fe(II), and Co(II) Aryloxides: Steric and Dispersion Effects and the Thermal Rearrangement of a Cobalt Aryloxide to a Co(II) Semiquinone Complex.

A series of Mn(II), Fe(II), and Co(II) bisaryloxide dimers ([M(OCH-2,4,6-Cy)] {M = Mn (), Fe (), and Co ()} were synthesized by the addition of 2,4,6-tricyclohexylphenol (HOCH-2,4,6-Cy) to the silyl amido dimers [M(N(SiMe))] (M = Mn, Fe, Co; Cy = cyclohexyl). An unexpected and unique Co(II) phenoxide derivative (), [Co(OCH-2,4,6-Cy)(OCH-3,5,6-Cy)], was obtained via ligand rearrangement of at ca. 180 °C.

Catalytic generation of -quinone dimethides donor/donor rhodium carbenes.

Substrates engineered to undergo a 1,4-C-H insertion to yield benzocyclobutenes resulted in a novel elimination reaction to yield -quinone dimethide (-QDM) intermediates that undergo Diels-Alder or hetero-Diels-Alder cycloadditions. The analogous benzylic acetals or ethers avoid the C-H insertion pathway completely and, after hydride transfer, undergo a de-aromatizing elimination reaction to -QDM at ambient temperature. The resulting dienes undergo a variety of cycloaddition reactions with high diastereo- and regio-selectivity.

Disproportionation of Sn(II){CH(SiMe)} to ˙Sn(III){CH(SiMe)} and ˙Sn(I){CH(SiMe)}: characterization of the Sn(I) product.

Half a century after the photolytic disproportionation of Lappert's dialkyl stannylene SnR, R = CH(SiMe) (1) gave the persistent trivalent radical [˙SnR], the characterization of the corresponding Sn(I) product, ˙SnR is now described. It was isolated as the hexastannaprismane SnR (2), from the reduction of 1 by the Mg(I)-reagent, Mg(BDI) (BDI = (DipNCMe)CH, Dip = 2,6-diisopropylphenyl).

London Dispersion Effects in a Distannene/Tristannane Equilibrium: Energies of their Interconversion and the Suppression of the Monomeric Stannylene Intermediate.

Reaction of {LiC H -2,4,6-Cyp ⋅Et O} (Cyp=cyclopentyl) (1) of the new dispersion energy donor (DED) ligand, 2,4,6-triscyclopentylphenyl with SnCl afforded a mixture of the distannene {Sn(C H -2,4,6-Cyp ) } (2), and the cyclotristannane {Sn(C H -2,4,6-Cyp ) } (3). 2 is favored in solution at higher temperature (345 K or above) whereas 3 is preferred near 298 K. Van't Hoff analysis revealed the 3 to 2 conversion has a ΔH=33.

Tuning the Intermediate Valence Behavior in the Zintl Compound YbZnSb by Incorporation of RE [YbREZnSb (0.2 ≤ ≤ 0.7), RE = Sc, Y, La, Lu and Gd].

The solid solutions of YbREZnSb (RE = Sc, Y, La, Lu, and Gd; 0.2 ≤ ≤ 0.7) were prepared to probe the intermediate valency of Yb in YbZnSb.

Strain-Release Pentafluorosulfanylation and Tetrafluoro(aryl)sulfanylation of [1.1.1]Propellane: Reactivity and Structural Insight.

We leveraged the recent increase in synthetic accessibility of SF Cl and Ar-SF Cl compounds to combine chemistry of the SF and SF Ar groups with strain-release functionalization. By effectively adding SF and SF Ar radicals across [1.1.