Palladium‐Catalyzed Carbonylative Difunctionalization of C=N Bond of Azaarenes or Imines to Quinazolinones

Supporting information for this article is given via a link at the end of the document. By intercepting the acylpalladium species with C=N bond of azaarenes or imines other than free amines or alcohols, the difunctionalization of C=N bond was established via palladium‐catalyzed carbonylation/nucleophilic addition sequence. This method is compatible with a diverse range of azaarenes and imines and allows for the efficient synthesis of a wide range of quinazolinones and derivatives. The synthetic utility has been demonstrated by one‐step synthesis of evodiamine and its analogue with inexpensive starting materials.     

The X‐ray Crystal Structures of Hg(C6F4X‐p)2 (X = NH2, OMe,or Me) – Two Examples of Supramolecular Lewis Acid/Base Complexes

The X‐ray crystal structures of Hg(C₆F₄X‐p)₂ (X = NH₂, OMe, or Me) show the compounds to have almost linear C–Hg–C stereochemistry (X = NH₂, 176.3(4)°; X = OMe, 179.5(2)°; X = Me, 176.3(2)°), and the two tetrafluoroaryl rings rotated ca. 52–62° with respect to each other. Substantial conjugation of NH₂ and OMe groups with the aromatic rings is evident from N–C and O–C(Ar) distances. For X = NH₂ or OMe, two weak N(O)–Hg coordination interactions per mercury lead to a two dimensional supramolecular chain structure containing pairs of π‐stacked aromatic rings at near van der Waals contact distances rotated at 62.2° (X = NH₂) or 52.9° (X = OMe) to each other. In Hg(C₆F₄Me‐p)₂, which does not have potential donor atoms, no supramolecular structure is obtained, the molecules being laterally displaced from one another.     

Crystal Structure Refinement of Lead Cyanamide and the Stiffness of the Cyanamide Anion

The crystal structure of lead cyanamide, PbNCN, has been refined on the basis of a single crystal grown from solution. PbNCN crystallizes in space group Pnma (Z = 4) with a = 555.66(4) pm, b = 386.77(2) pm, and c = 1173.50(8) pm. The cyanamide anion exhibits C–N bond lengths of 116 pm and 130 pm, and the N–C–N angle is 176°. Quantum‐chemical DFT calculations indicate that the cyanamide unit is comparatively easy to distort.     

6‐Amino‐3‐methyl‐5‐nitro­so­pyrimi­dine‐2,4(1H,3H)‐dione forms a three‐dimensional hydrogen‐bonded framework structure

Molecules of the title compound, C₅H₆N₄O₃, are linked into a single three‐dimensional framework by a two‐centre N—H⃛O hydrogen bond [H⃛O = 1.92 Å, N⃛O = 2.785 (2) Å and N—H⃛O = 168°], a two‐centre N—H⃛H hydrogen bond [H⃛N = 2.19 Å, N⃛N = 3.017 (2) Å and N—H⃛N = 157°] and the intermolecular component of an effectively planar three‐centre N—H⃛(O)₂ hydrogen bond [H⃛O = 2.03 and 2.31 Å, N⃛O = 2.645 (2) and 2.957 (2) Å, N—H⃛O = 126 and 130°, and O⃛H⃛O = 101°].     

Untersuchungen am Chlordiphenyl‐ und Tribenzylstiban sowie am Tribenzyldibromstiboran – Molekülstrukturen und Isotypie

Element–Element Bonds. X. Studies of Chloro(diphenyl)stibane, Tribenzylstibane and Tribenzyldibromostiborane – Molecular Structures and Isotypism Chlorodiphenylstibane ( 1 d ) {P2₁/c; Z = 4; a = 1191.8(1); b = 853.4(1); c = 1112.0(1) pm; β = 93.60(1)°; –100 ± 2 °C} crystallizes isotypically with a series of homologous (H₅C₆)₂E–X compounds (E = As, X = Cl, Br, I; E = Sb, X = Br, I); the structure type of tribenzylstibane ( 5 d ) {Pbca; Z = 8; a = 832.1(2); b = 2681.3(5) pm; c = 1600.9(3); –100 ± 3 °C} is already known from tribenzylmethanol, ‐silanol and ‐silane. Tribenzyldibromostiborane ( 6 ) {P2₁/n; Z = 4; a = 938.4(2); b = 2292.4(5); c = 1019.7(2) pm; β = 112.71(1)°; –100 ± 3 °C} does not show an analogous relationship to known structure types. Characteristic mean bond lengths and angles are { 1 d , Sb–Cl 240.9(1), Sb–C 214.0 pm, Cl–Sb–C 93.8°, C–Sb–C 98.6(1)°; 5 d , Sb–C 217.5(3) pm, C–Sb–C 94.9(6)°; 6 , Sb–Br 264.6; Sb–C 217.0(8) pm, Br–Sb–Br 179.4(1)°; C–Sb–C 120°; Br–Sb–C 84.8(2)° to 94.7(2)°}. Stiborane 6 exhibits very weak intermolecular Sb‥Br interactions of 417 pm which, however, affect the molecular conformation in a striking way.     

Activated sterically strained C=N bond in N-substituted p-quinone mono- and diimines: XIV. Reaction of some 3,5-dimethyl-1,4-benzoquinone monoimines with alcohols

Steric strain in the C=N-C fragment in 3,5-disubstituted N-acyl-1,4-benzoquinone monoimines, unlike their N-arylsulfonyl analogs, leads to increase of the C=N-C angle above 130° or twisting of the double C=N bond and loss of planarity of the quinoid ring. This structural transformation enhances the reactivity of the C=N bond so that 1,2-addition of alcohols becomes possible with formation of sterically unstrained cyclohexadienone structure with sp ³-hybridized C⁴ carbon atom.     

Darstellung von Organylquecksilber(II)‐di(methansulfonyl)amiden und Kristallstruktur von Ph–Hg–N(SO2Me)2

Polysulfonylamines. CXXIV. Preparation of Organylmercury(II) Di(methanesulfonyl)amides and Crystal Structure of Ph–Hg–N(SO₂Me)₂ Four N,N‐disulfonylated organylmercury(II) amides R–Hg–N(SO₂Me)₂, where R is Me, ⁱPr, Me₃SiCH₂ or Ph, were obtained on treating the appropriate chlorides RHgCl with AgN(SO₂Me)₂, and characterized by ¹H and ¹³C NMR spectra. In the crystal structure of the phenyl compound (orthorhombic, space group Pbca, Z = 8, X‐ray diffraction at –95 °C), the molecule exhibits a covalent and significantly bent C–Hg–N grouping [bond angle 172.7(3)°; Hg–C 204.0(8), Hg–N 209.1(7) pm]. One sulfonyl oxygen atom forms a short intramolecular Hg…O contact [296.1(5) pm] and simultaneously catenates glide‐plane related molecules via a second Hg…O interaction 297.6(5) pm], thus conferring upon Hg^II the effective coordination number 4 and a geometrically irregular coordination polyhedron (bond angles from 173 to 54°).     

Simplicity Beneath Complexity: Counting Molecular Electrons Reveals Transients and Kinetics of Photodissociation Reactions

Time‐resolved pump–probe gas‐phase X‐ray scattering signals, extrapolated to zero momentum transfer, provide a measure of the number of electrons in a system, an effect that arises from the coherent addition of elastic scattering from the electrons. This allows to identify reactive transients and determine the chemical reaction kinetics without the need for extensive scattering simulations or complicated inversion of scattering data. We examine the photodissociation reaction of trimethylamine and identify two reaction paths upon excitation to the 3p state at 200 nm: a fast dissociation path out of the 3p state to the dimethyl amine radical (16.6±1.2 %) and a slower dissociation via internal conversion to the 3s state (83.4±1.2 %). The time constants for the two reactions are 640±130 fs and 74±6 ps, respectively. Additionally, it is found that the transient dimethyl amine radical has a N?C bond length of 1.45±0.02 Å and a C?N?C bond angle of 118°±4°.     

Polysulfonylamine. CLXXXIV. Kristallstrukturen molekularer Triphenylphosphangold(I)‐di(4‐X‐benzolsulfonyl)‐amide: Isomorphie und dichte Packung (X = Me,F, Cl,NO2) vs. struktursteuernde Halogenbrücken C–X···Au/O (X = Br,I)

Polysulfonylamines. CLXXXIV. Crystal Structures of Molecular Triphenylphosphanegold(I) Di(4‐X‐benzenesulfonyl)amides: Isomorphism and Close Packing (X = Me, F, Cl, NO₂) vs. Structure‐Determining C–X···Au/O Halogen Bonds (X = Br, I) In order to study the structure‐determining influence that halogen bonding can exert during the course of crystallization, solid‐state structures are compared for two previously reported and four new molecular gold(I) complexes of the type Ph₃P–Au–N(SO₂–C₆H₄–4‐X)₂, each featuring linear P,N coordination at gold and two phenyl rings with varying p‐substituents X = Me, F, Cl, NO₂, Br or I. The compounds were synthesized by reactions of Ph₃PAuX (X = Cl or I) with the corresponding silver di(arenesulfonyl)amides, crystallized from dichloromethane, and characterized by low‐temperature X‐ray diffraction. The Me, F, Cl and NO₂ congeners are isomorphic and crystallize without solvent inclusion in the chiral orthorhombic space group P2₁2₁2₁ (Z′ = 1). These structures are governed by isotropic close packing via three‐dimensional 2₁ symmetry, incidentally supported by an invariant set of C–H···O=S hydrogen bonds, CH/π interactions and π/π stackings of aromatic rings; in particular, the hard halogen atoms of the fluoro and the chloro homologues are not involved in X···Au, X···O or X···X interactions. The higher homologues, with soft halogen atoms, were obtained as a dichloromethane hemisolvate for X = Br and a corresponding monosolvate for X = I, each triclinic in the centrosymmetric space group (Z′ = 1). Here, the primary structural effect is implemented by infinite chains in which translation‐related molecules are connected for the bromo compound by a bifurcated Au···Br(2)···O=S interaction, for the iodo congener by an equivalent Au···I(2)···O=S interaction and a short halogen bond C–I(1)···O=S. The latter bond is stronger than a similar C–Br···O=S interaction and induces a conformational adjustment of the (CSO₂)₂N group from the normal twofold symmetry in the bromo compound to an energetically unfavourable asymmetric form in the iodo homologue. In both cases, pairs of antiparallel molecular catemers are associated into strands via sixfold phenyl embraces, the strands are stacked to form layers, the solvent molecules are intercalated between adjacent layers, and the crystal packings are reinforced by a number of C–H···O=S hydrogen bonds and interactions of aromatic rings.     

Bilayers in 4‐iodo‐N‐(2‐iodo‐4‐nitrophenyl)benzamide generated by a combination of an N—H⋯O=C hydrogen bond and two independent iodo–nitro interactions

Molecules of the title compound, C₁₃H₈I₂N₂O₃, are linked into C(4) chains by a single N—H⋯O=C hydrogen bond [H⋯O = 2.10 Å, N⋯O = 2.832 (5) Å and N—H⋯O = 140°]. Two independent two‐centre iodo–nitro interactions, both involving the same O atom but different I atoms [I⋯O = 3.205 (3) and 3.400 (3) Å, and C—I⋯O = 160.4 (2) and 155.7 (2)°], link the hydrogen‐bonded chains into bilayers.     

C−X Bond Activation by Palladium: Steric Shielding versus Steric Attraction

The C−X bond activation (X = H, C) of a series of substituted C(n°)−H and C(n°)−C(m°) bonds with C(n°) and C(m°) = H₃C− (methyl, 0°), CH₃H₂C− (primary, 1°), (CH₃)₂HC− (secondary, 2°), (CH₃)₃C− (tertiary, 3°) by palladium were investigated using relativistic dispersion-corrected density functional theory at ZORA-BLYP-D3(BJ)/TZ2P. The effect of the stepwise introduction of substituents was pinpointed at the C−X bond on the bond activation process. The C(n°)−X bonds become substantially weaker going from C(0°)−X, to C(1°)−X, to C(2°)−X, to C(3°)−X because of the increasing steric repulsion between the C(n°)- and X-group. Interestingly, this often does not lead to a lower barrier for the C(n°)−X bond activation. The C−H activation barrier, for example, decreases from C(0°)−X, to C(1°)−X, to C(2°)−X and then increases again for the very crowded C(3°)−X bond. For the more congested C−C bond, in contrast, the activation barrier always increases as the degree of substitution is increased. Our activation strain and matching energy decomposition analyses reveal that these differences in C−H and C−C bond activation can be traced back to the opposing interplay between steric repulsion across the C−X bond versus that between the catalyst and substrate.     

2,2′‐[2,3‐Di­hydro‐2‐(prop‐2‐enyl)‐1H‐isoindole‐1,3‐diyl­idene]bis(propane­di­nitrile)–tetra­thia­fulvalene (1/1), TCPI–TTF

The title complex, C₁₇H₉N₅·C₆H₄S₄, contains π‐deficient bis(di­nitrile) and TTF mol­ecules stacked alternately in columns along the a‐axis direction; the interplanar angle between the TTF molecule and the isoindolinyl C₄N[C(CN)₂]₂ moiety is 1.21 (4)°. The N‐allyl moiety in the TCPI mol­ecule is oriented at an angle of 87.10 (10)° with respect to the five‐membered C₄N ring, and the four C[triple‐bond]N bond lengths range from 1.134 (3) to 1.142 (3) Å, with C—C[triple‐bond]N angles in the range 174.3 (3)–176.9 (2)°. In the TTF system, the S—C bond lengths are 1.726 (3)–1.740 (3) and 1.751 (2)–1.763 (2) Å for the external S—C(H) and internal S—C(S) bonds, respectively.     

7‐Amino‐1‐(2‐deoxy‐β‐erythro‐pentofuranosyl)‐1H‐1,2,3‐triazolo[4,5‐d]pyrimidine: an 8‐azaadenine nucleoside with the nucleobase in a syn conformation

The title compound, C₉H₁₂N₆O₃, shows a syn‐glycosylic bond orientation [χ = 64.17 (16)°]. The 2′‐deoxyfuranosyl moiety exhibits an unusual C1′‐exo–O4′‐endo (₁T⁰; S‐type) sugar pucker, with P = 111.5 (1)° and τ_m = 40.3 (1)°. The conformation at the exocyclic C4′—C5′ bond is +sc (gauche), with γ = 64.4 (1)°. The two‐dimensional hydrogen‐bonded network is built from intermolecular N—H...O and O—H...N hydrogen bonds. An intramolecular bifurcated hydrogen bond, with an amino N—H group as hydrogen‐bond donor and the ring and hydroxymethyl O atoms of the sugar moiety as acceptors, constrains the overall conformation of the nucleoside.     

Imines in the Titanium Coordination Sphere – Transformation of Imidoyl Chlorides to Nitrilium Ions

In the reaction of TiCl₄ in benzene as solvent with the imidoyl chloride p‐Tolyl(Cl)C=NPh ( 1 ) the abstraction of the chloride substituent is observed, leading to the nitrilium salt [p‐Tolyl–C≡N–Ph]⁺[Ti₂Cl₉]^– ( 2 ) in quantitative yield. The highly electrophilic salt 2 is characterized by IR‐ and NMR spectroscopy. The observed band for the C≡N stretching mode of 2 clearly indicates the formation of a nitrilium ion. Especially a characteristic line broadening of the ¹³C{¹H}‐NMR signals related to carbon atoms next to the nitrogen is observed. By ¹⁵N,¹H‐HMBC NMR experiments it is shown that the nitrogen signal of 2 is significantly shifted to high‐field in relation to nitriles and imines. The molecular structure of 2 was confirmed by single‐crystal X‐ray diffraction. The C≡N bond length and the linearity of the C–C≡N–C unit in 2 confirm the triple bond character of this bond.     

4‐Iodo‐N‐(2‐nitro­phenyl­sulfanyl)­aniline: π‐stacked sheets generated by a combination of N—H⃛O and C—H⃛O hydrogen bonds

Molecules of the title compound, C₁₂H₉IN₂O₂S, are linked by one N—H⃛O hydrogen bond [H⃛O = 2.16 Å, N⃛O = 2.935 (4) Å and N—H⃛O 147°] and two C—H⃛O hydrogen bonds [H⃛O both 2.49 Å, C⃛O = 3.231 (5) and 3.220 (5) Å, and C—H⃛O = 135 and 134°] into sheets which themselves are weakly linked by an aromatic π–π‐stacking interaction between iodinated rings in centrosymmetrically related mole­cules. There are no iodo–nitro interactions.     

1,3‐Bis[2‐(2‐hydroxybenzylideneamino)phenoxy]propane

The title compound {systematic name: 2,2′‐[1,3‐propanediyldioxydi‐o‐phenylenebis(nitrilomethylidyne)]diphenol}, C₂₉H₂₆N₂O₄, exists as the phenol–imine form in the crystal, and there are strong intramolecular O—H⋯N hydrogen bonds, with O⋯N distances of 2.545 (2) and 2.579 (2) Å. The C=N imine bond distances are in the range 1.276 (2)–1.279 (2) Å and the C=N—C bond angles are in the range 123.05 (16)–124.64 (17)°. The configurations about the C=N bonds are anti (1E).     

Die Kristallstruktur von Ph3PNBr · Br2

Crystal Structure of Ph₃PNBr · Br₂ Ph₃PNBr · Br₂ ( 1 ) has been prepared besides of other products from the reaction of Ph₃PNH with bromine, forming orange‐yellow single crystals which are characterized by IR‐spectroscopy and by a crystal structure determination. Space group P2₁/n, Z = 4, lattice dimensions at 20 °C: a = 916.76(10), b = 1351.42(8), c = 1494.9(2) pm, β = 96.191(5)°, R₁ = 0.0538. 1 has a molecular structure in which the Br₂ molecule is coordinated at the nitrogen atom of the N‐bromine‐phosphoraneimine Ph₃PNBr in a linear arrangement N–Br–Br with bond lengths N–Br of 224.5(6) pm and Br–Br of 248.4(1) pm. The nitrogen atom of 1 is ψ‐tetrahedrally coordinated in addition by the phosphorus atom with a P–N distance of 165.3(6) pm and by the covalently bonded bromine atom with a bond length of 188.9(6) pm.     

Addition of Me3SiCN to trifluoromethyl derivates of N‐(pyridylmethylidene) anilines catalyzed by Lewis acids

A series of novel Shiff bases (1a–h) was synthesized by condensation of pyridinecarboxaldehydes (1–4) with 3‐ and 4‐trifluoromethylanilines (5, 6) in the presence of molecular sieves (4 Å). It was found that AlCl₃ and AlBr₃ catalyzed the addition of Me₃SiCN to the C?N bond of the imines obtained, whereas the other Lewis acids studied (YCl₃, LaCl₃, ZnI₂) were not active. The reactivity of the imines in the title reaction, on the whole, correlated with their basicity. Besides the addition giving the expected α‐amino nitriles (2a,b,d–f,h), an unusual reaction leading to unsaturated nitriles (3a–h) was observed. The structures of saturated and unsaturated products 2d and 3c were determined by X‐ray diffraction. Copyright © 2001 John Wiley & Sons, Ltd.     

Substituent Effects on Site Selectivity (C=C vs C=N) in Heterocumulene-Heterodiene [4 + 2] Cycloadditions: Density Functional and Semiempirical AM1 Molecular Orbital Calculations

The effect of substituents on the site selectivity (C=C vs C=N) in the [4 + 2] cycloaddition between heterocumulenes (ketene imines) 2a-g with heterodienes (acroleines 9a-n and 4-acylfuran-2,3-diones 1a-d) is treated by semiempirical AM1 molecular orbital and density functional calculations using Becke's three-parameter hybrid method (B3LYP/6-31G). For some reactions calculations were also done at the B3LYP/6-31+G level of theory. For reaction of the oxa 1,3-dienes with ketene imines unsubstituted at the terminal carbon invariably addition across the C=C heterocumulene double bond has a lower activation energy than addition across the C=N double bond. Substitution of methyl or especially phenyl groups at the ketene imine C-terminus leads to a reversal of the respective activation energies. Incorporation of the oxa 1,3-diene system into the heterocyclic dione 1 substantially enhances the reactivity ( approximately 10 kcal mol(-1) lower activation energies) as compared to similarly substituted acroleins. At the DFT level of theory all reactions are found to proceed via a concerted asynchronous mechanism.     

Iridium‐Catalyzed Asymmetric Hydrogenation of Imines

We have evaluated a wide range of iridium complexes derived from chiral oxazoline‐based N,P ligands for the asymmetric hydrogenation of imines and identified three efficient catalysts. These catalysts are readily synthesized by straightforward convenient routes and are air and moisture stable. In the reduction of acetophenone N‐arylimines and related acyclic substrates, excellent enantioselectivities (up to 96 % ee) were obtained by using 0.1–0.5 mol % of catalyst at ?20 °C and 5–50 bar hydrogen pressure.