Hydrogen bonding in C‐substituted nitroanilines: molecular ladders in 2‐trifluoromethyl‐4‐nitroaniline and sheets of R(12) and R(32) rings in 3‐trifluoromethyl‐4‐nitroaniline

In 2‐tri­fluoro­methyl‐4‐nitro­aniline, C₇H₅F₃N₂O₂, (I), the mol­ecules lie across a mirror plane in space group Pnma. The mol­ecules are linked by paired N—H?O hydrogen bonds to form a C(8)[R(6)] chain of rings, pairs of which are linked into a molecular ladder by a single C—H?O hydrogen bond. The isomeric 3‐tri­fluoro­methyl‐4‐nitro­aniline, (II), has Z′ = 2 in space group P2₁/c. Each mol­ecule is linked to four others by N—H?O hydrogen bonds to form sheets built from alternating R(12) and R(32) rings.     

Hydro­gen bonding in C‐substituted nitro­anilines: a chain of R(12) rings in 2‐methane­sulfonyl‐4‐nitro­aniline

The title compound, C₇H₈N₂O₄S, exhibits a markedly polarized molecular–electronic structure. The mol­ecules are linked into a chain of edge‐fused (12) rings by two N—H⋯Ozdbnd;S hydrogen bonds [H⋯O = 2.10 and 2.21 Å, N⋯O = 2.900 (2) and 2.878 (2) Å, and N—H⋯O = 152 and 133°].     

Soft C—H⃛O hydrogen bonds in methyl 2,4‐di­nitro­benzene­sulfenate: sheets built from R22(10) and R66(42) rings

Molecules of the title compound, C₇H₆N₂O₅S, are linked into sheets containing R₂²(10) and R₆⁶(42) rings by C—H?O hydrogen bonds [C?O 3.405 (3) and 3.511 (2) Å; C—H?O 159 and 169°], in which both acceptors are in the same nitro group. Comparisons are made with the hydrogen bonding in other nitro­benzene­sulfenate esters.     

2‐Cyano‐4‐iodoacetanilide: a hydrogen‐bonded chain of R22(12) and R22(14) rings

The molecules of 2‐cyano‐4‐iodoacetanilide, C₉H₇IN₂O, are linked by N—H...N and C—H...O hydrogen bonds into chains of alternating R₂²(12) and R₂²(14) rings.     

5‐Amino‐3‐tert‐butyl‐1‐(4‐nitro­phen­yl)‐1H‐pyrazole forms hydrogen‐bonded sheets of alternating R(20) and R(32) rings

Molecules of the title compound, C₁₃H₁₆N₄O₂, are linked by one N—H⋯O hydrogen bond [H⋯O = 2.47 Å, N⋯O = 3.326 (2) Å and N—H⋯O = 166°] and one N—H⋯N hydrogen bond [H⋯N = 2.19 Å, N⋯N = 3.063 (2) Å and N—H⋯N = 173°] into sheets containing alternating (20) and (32) rings, both types of which are centrosymmetric.     

Methyl 4‐amino‐2,3‐dihydro‐6‐methoxy‐1,3‐dioxo‐1H‐pyrrolo[3,4‐c]pyridine‐7‐carboxylate forms hydrogen‐bonded sheets built from R22(8) and R66(42) rings

In the title compound, C₁₀H₉N₃O₅, which was formed by the reaction of 6‐amino‐2‐methoxy‐4(3H)‐pyrimidinone with di­methyl acetyl­enedi­carboxyl­ate, the mol­ecules are linked by N—H?O hydrogen bonds [N?O 2.8974 (15) and 3.0300 (15) Å, and N—H?O 165 and 174°] into planar sheets built from alternating R₂²(8) and R₆⁶(42) rings.     

Hydrogen bonding in nitroaniline analogues: hydrogen‐bonded sheets in 2‐amino‐4,6‐dimethoxy‐5‐nitropyrimidine and π‐stacked hydrogen‐bonded sheets in 4‐amino‐2,6‐dimethoxy‐5‐nitropyrimidine

In 2‐amino‐4,6‐di­methoxy‐5‐nitro­pyrimidine, C₆H₈N₄O₄, the mol­ecules are linked by one N—H⋯N and one N—H⋯O hydrogen bond to form sheets built from alternating R(8) and R(32) rings. In isomeric 4‐amino‐2,6‐di­methoxy‐5‐nitro­pyrimidine, C₆H₈N₄O₄, which crystallizes with Z′ = 2 in P, the two independent mol­ecules are linked into a dimer by two independent N—H⋯N hydrogen bonds. These dimers are linked into sheets by a combination of two‐centre C—H⋯O and three‐centre C—H⋯(O)₂ hydrogen bonds, and the sheets are further linked by two independent aromatic π–π‐stacking interactions to form a three‐dimensional structure.     

2‐Amino‐4‐chloro‐5‐formyl‐6‐[methyl(2‐methylphenyl)amino]pyrimidine and 2‐amino‐4‐chloro‐5‐formyl‐6‐[(2‐methoxyphenyl)methylamino]pyrimidine are isostructural and form hydrogen‐bonded sheets of R22(8) and R66(32) rings

2‐Amino‐4‐chloro‐5‐formyl‐6‐[methyl(2‐methylphenyl)amino]pyrimidine, C₁₃H₁₃ClN₄O, (I), and 2‐amino‐4‐chloro‐5‐formyl‐6‐[(2‐methoxyphenyl)methylamino]pyrimidine, C₁₃H₁₃ClN₄O₂, (II), are isostructural and essentially isomorphous. Although the pyrimidine rings in each compound are planar, the ring‐substituent atoms show significant displacements from this plane, and the bond distances provide evidence for polarization of the electronic structures. In each compound, a combination of N—H...N and N—H...O hydrogen bonds links the molecules into sheets built from centrosymmetric R₂²(8) and R₆⁶(32) rings. The significance of this study lies in its observation of the isostructural nature of (I) and (II), and in the comparison of their crystal and molecular structures with those of analogous compounds.     

Reaction of 3‐substituted and 4‐bromo‐3‐substituted isoquinolin‐1‐(2h)‐ones with propargyl bromide

Isoquinolinones were brominated using N‐bromosuccinimide in dimethylformamide at room temperature to give 4‐bromo‐3‐substituted isoquinolin‐1‐(2H)‐ones. The reaction of these isoquinolinones with propargyl bromide in the presence of anhydrous potassium carbonate yielded N and O‐alkylated products.     

Diversification of 6‐bromo‐2‐substituted Pyridine Derivatives via Suzuki‐Miyaura Cross‐Coupling

The functionalized pyridine ring is a ubiquitous moiety in numerous research areas including materials, natural products, as well as agrochemicals and is a strategic synthon for heteroaromatic synthetic method development. Pyridinyl ligand scaffolds are also frequently incorporated into the study of metal complexes for pharmaceutical applications or separation science. Convergent access to advanced synthons is critical to experimentally defining structure activity relationships and improvement of molecular performance in the aforementioned areas. The current work describes an efficient catalyst/ligand combination for accessing 2‐acetyl‐ and 2‐procarbonyl substituted pyridines via Suzuki‐Miyaura cross‐coupling with various organotrifluoroborates. Twenty examples are described with carbonyl and procarbonyl functional groups which afford subsequent access to diversified unsymmetric ketones. Substrate scope and limitation in addition to a scale up experiment are reported.     

(1R,2R)‐2‐(4‐Methylenecyclohex‐2‐enyl)propyl (1R,4S)‐camphanate

Esterification of a single diastereomer of 2‐(4‐methylene­cyclohex‐2‐enyl)propanol, (II), with (1R,4S)‐(+)‐camphanic acid [(1R,4S)‐4,7,7‐trimethyl‐3‐oxo‐2‐oxabicyclo[2.2.1]heptane‐1‐carboxylic acid] leads to the crystalline title compound, C₂₀H₂₈O₄. The relative configuration of the camphanate was determined by X‐ray diffraction analysis. The outcome clarifies the relative and absolute stereochemistry of the naturally occurring bisabolane sesquiterpenes β‐turmerone and β‐sesquiphellandrene, since we have converted (II) into both natural products via a stereospecific route.     

2‐{2‐[2‐(4‐Methoxybenzoyl)ethylamino]‐4‐nitroanilino}ethyl acetate: complex sheets built from five independent hydrogen bonds

The molecules of the title compound, C₂₀H₂₃N₃O₆, are almost completely planar, apart from the H atoms bonded to tetrahedral C atoms. A combination of five hydrogen bonds, one of the N—H...O type and two each of the C—H...O and C—H...π(arene) types, links the molecules into complex sheets.     

rac‐(Z)‐Ethyl 2‐bromo‐2‐[(3R,5R)‐3‐bromo‐5‐methyl­tetra­hydro­furan‐2‐yl­idene]acetate

In the title compound, C₉H₁₂Br₂O₃, a (tetra­hydro­furan‐2‐yl­idene)acetate, the double bond has the Z form. In the tetra­hydro­furan group, the relative configuration of the Br atom in the 3‐position and the methyl group in the 5‐position is anti. The compound crystallizes with two independent mol­ecules per asymmetric unit and, in the crystal structure, the individual mol­ecules are linked to their symmetry‐equivalent mol­ecules by C—H⋯O hydrogen bonds, so forming centrosymmetric hydrogen‐bonded dimers.     

[Na(DB18-C-6)(H2O)2][Na(DB18-C-6)(SCN)2]：Two-Di-mensional Network Complex Assembled by π-π Stacking Interactios,Hydrogen Bonds and Electrostatic Interactions

A novel two‐dimensional network dibenzo‐18‐crown‐6 (DB18‐C6) complex: [Na (DB18‐C‐6) (H₂O)₂] [Na (DB18‐C‐6) (SCN)₂] has been isolated and characterized by elemental, IR and X‐ray diffraction analysis. The crystal structure belongs to monoclinic, space group P2₁/c with cell dimensions a = 1.06178(7), b = 1.40243(8), c = 3.03496(19) nm, β = 90.4220(10)°, V = 4.5292(5) nm³, Z=4, D_calcd =1.351 g/ cm³, F(000) = 1936, R₁ = 0.0369, wR₂ = 0.0821. The most interesting feature in this structure is that complex cation and complex anion form a two‐dimensional network via τ‐τ stacking interactions, hydrogen bonds and electrostatic interactions.     

(E)‐N′‐[5‐Chloro‐3‐methoxy‐2‐(4‐methylphenylsulfonyloxy)benzylidene]isonicotinohydrazide acetic acid solvate: hydrogen‐bonded network of alternating R44(42), R55(33) and R66(40) rings

In the title compound, C₂₁H₁₈ClN₃O₅S·C₂H₄O₂, a combination of O—H...O, N—H...O, C—H...O and C—H...N hydrogen bonds links the components into a complex network containing alternating R₄⁴(42), R₅⁵(33) and R₆⁶(40) rings.     

Hydrogen bonding in two salts of 3‐methylthio‐4‐(propargylthio)quinoline

In 3‐methyl­thio‐4‐(propargyl­thio)­quinolinium chloride monohydrate, C₁₃H₁₂NS₂⁺·Cl^?·H₂O, and 3‐methyl­thio‐4‐(propargyl­thio)­quinolinium tri­chloro­acetate, C₁₃H₁₂­NS₂⁺·­C₂Cl₃O₂^?, the terminal alkyne group forms C[triple‐bond]C—H?O hydrogen bonds of favourable geometry. The conformation of the flexible propargyl­thio group is different in the two structures.     

2‐{[(Dodecylsulfanyl)carbonothioyl]sulfanyl}‐2‐methylpropanoic acid: a chain of edge‐fused R22(8) and R44(20) rings built from O—H...O and C—H...O hydrogen bonds

In the title compound, C₁₇H₃₂O₂S₃, the dodecyl chain and the trithiocarbonate unit adopt a nearly planar all‐trans conformation, while the carboxyl group is synclinal to this chain direction. The molecules are linked by pairs of inversion‐related O—H...O hydrogen bonds to form centrosymmetric dimers of R₂²(8) type, and dimers related by translation are linked by C—H...O hydrogen bonds to form a chain of edge‐fused rings, or a molecular ladder, containing alternating R₂²(8) and R₄⁴(20) rings.     

Hydrogen‐bonded sheets of R22(10) and R44(24) rings in 1‐deoxy‐1‐morpholino‐d‐fructopyranose

In the title compound, C₁₀H₁₉NO₆, both rings adopt almost perfect chair conformations and their mutual orientation is influenced by an intramolecular O—H...N hydrogen bond. The molecules are linked by three independent O—H...O hydrogen bonds into sheets containing equal numbers of R₂²(10) and R₄⁴(24) rings.     

Tetraaqua‐1κ4O‐bis(ɛ‐caprolactam‐1κO)‐μ‐cyano‐1:2κ2N:C‐pentacyano‐2κ5C‐iron(III)yttrium(III), a novel cyano‐bridged dinuclear complex

Using caprolactam as a ligand, the novel title cyano‐bridged yttrium(III)–ferricyanide complex, [Y(caprolactam)₂(H₂O)₄Fe(CN)₆] or [FeY(CN)₆(C₆H₁₁NO)₂(H₂O)₄], has been synthesized and structurally characterized. The Y atom is seven‐coordinate and has approximately pentagonal–bipyramidal stereochemistry, with water mol­ecules occupying apical positions. Of the five ligands in equatorial positions, one is the N‐bound bridging cyano group, and flanking this are two O‐­bound caprolactam moieties, which are markedly inclined towards the bridged ferricyanide moiety such that they partially envelop it. Water mol­ecules occupy the remaining two equatorial positions. The Y—N—C—Fe—C—N sequence of atoms lies on a crystallographic twofold axis and is therefore perfectly linear, which has not been observed previously in cyano‐bridged bimetallic complexes.     

Synthesis of functional phosphines with ortho‐substituted aryl groups: 2‐RC6H4PH2 and 2‐RC6H4P(SiMe3)2 (R = 2‐i‐Pr‐ or 2‐t‐Bu‐)

The synthesis and characterization of 2‐i‐PrC₆H₄PCl₂ ( 3 ), 2‐t‐BuC₆H₄PCl₂ ( 4 ), 2‐i‐PrC₆H₄PH₂ ( 5 ), 2‐t‐BuC₆H₄PH₂ ( 6 ), 2‐i‐PrC₆H₄P(SiMe₃)₂ ( 7 ), and 2‐t‐BuC₆H₄P(SiMe₃)₂ ( 8 ) are described. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:265–270, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20606