Crystallographic report: 1,1‐Diphenyl‐3‐(triphenylgermyl)‐3‐(4‐chlorophenyl) propanol

The germanium atom in [(C₆H₅)₃GeCH(4‐ClC₆H₄)CH₂C(C₆H₅)₂OH] is in a distorted tetrahedral geometry. Steric hindrance precludes O? H···O intra‐ or inter‐molecular bonding. Copyright © 2005 John Wiley & Sons, Ltd.     

5‐Bromo‐2,3‐dihydro‐4‐methyl‐3‐nitrothiophene 1,1‐dioxide

The title compound, C₅H₆BrNO₄S, crystallizes in the centrosymmetric space group P2₁/c. Three weak C—H⃛O hydrogen bonds dominate the packing of the mol­ecules in the solid. These weak hydrogen bonds and a short intermolecular O⃛Br contact of 3.003 (2) Å are discussed using a Mulliken population analysis.     

Poly[(μ3‐1,1‐dioxo‐1,2‐benzoisothiazole‐3‐thiolato‐κ3N:S3:S3)silver(I)]

The centrosymmetric title compound, [Ag(C₇H₄NO₂S₂)]_n, consists of dinuclear units in which two thiosaccharinate anions each bridge two Ag atoms via an endocyclic N atom and an exocyclic S atom across a crystallographic centre of inversion midway between the Ag atoms. The dimeric units are connected via Ag—S_exo interactions to create two‐dimensional networks. The thiosaccharinate anions bridge in a μ₃‐S:S:N manner. The Ag...Ag distance can be considered a strong argentophilic interaction.     

A novel photoisomerzation of 1,2‐benzothiazine 1,1‐dioxides to 1,3‐benzothiazine 1,1‐dioxides

A novel facile photoconversion of 4‐hydroxy‐1,2‐bezothiazine 1,1‐dioxides ( 3a‐e ) into 4‐oxo‐1,3‐2H‐benzothiazine 1,1‐dioxides ( 4a‐e ) and 4‐hydroxy‐2‐methyl‐N‐(pyridin‐2‐yl)‐2H‐1,2‐benzothiazine‐3‐carboxamide 1,1‐dioxide (PRX) into N‐methyl saccharin ( 2 ) upon 254 nm irradiation in methanol or acetonitrile is reported. The structures of the products have been elucidated by spectroscopic methods and single crystal X‐ray structure determination for 4a and 4d .     

(3R*,3′R*)‐1,1′‐Dimethyl‐3,3′‐biindoline‐2,2′‐dithione

The (3R*,3′R*) configuration of the title compound, C₁₈H₁₆N₂S₂, (I), has been unambiguously elucidated by X‐­ray analysis. Mol­ecules of (I) have C₂ symmetry to a good approximation and a strongly folded shape. The interplanar angle between the two halves of a mol­ecule is 67.11 (6)°.     

(η6‐2‐Bromo‐1,1′‐biphenyl)tricarbonylchromium

The title compound, [Cr(C₁₂H₉Br)(CO)₃], crystallizes in the triclinic space group with close Br⋯Br separations. These contacts, along with several other factors, influence the (Ph)C—C(o‐BrC₆H₄) dihedral angle of 58.82 (6)°. The typical piano‐stool coordination about the Cr atom is in excellent agreement with the results of density functional theory calculations.     

Copper‐Mediated Aromatic 1,1‐Difluoroethylation with (1,1‐Difluoroethyl)trimethylsilane (TMSCF2CH3)

A new method for the formation of 1,1‐difluoroethyl copper species (“CuCF₂CH₃”) with 1,1‐difluoroethylsilane (TMSCF₂CH₃) has been developed. The “CuCF₂CH₃” species can be applied to the efficient 1,1‐difluoroethylation of diaryliodonium salts under mild conditions, affording (1,1‐difluoroethyl)arenes in good to excellent yields. This convenient procedure tolerates a wide range of functional groups and thus serves as a practical synthetic tool for the introduction of CF₂CH₃ group(s) into complex molecules.     

A novel synthesis of 5‐aryl‐3‐phenylpyrazole from 2‐aryl‐3‐benzoyl‐1,1‐cyclopropanedicarbonitrile and hydrazine

A new process for synthesis of 5‐aryl‐3‐phenylpyrazole is achieved. The regioselective ring‐opening reaction of 2‐aryl‐3‐benzoyl‐1,1‐cyclopropanedicarbonitrile with hydrazine plays a crucial role in the described process.     

Properties and Reactions of Substituted 1,2‐Thiazetidine 1,1‐Dioxides: Chiral Mono‐ and Bicyclic 1,2‐Thiazetidine 1,1‐Dioxides from α‐Amino Acids

New chiral mono‐ and bicyclic β‐sultams, valuable building blocks for drug synthesis, have been prepared from L ‐Ala, L ‐Val, L ‐Leu, L ‐Ile, L ‐Phe, L ‐Cys, L ‐Ser, L ‐Thr, and D ‐penicillamine by transformation of the COOH group into a methylsulfonyl chloride function, followed by cyclization under basic conditions. Selected properties, derivatives, and reactions of the β‐sultams are described.     

Catalyst‐Controlled 1,2‐ and 1,1‐Arylboration of α‐Alkyl Alkenyl Arenes

Two methods are reported for the 1,2‐ and 1,1‐arylboration of α‐methyl vinyl arenes. In the case of 1,2‐arylboration, the formation of a quaternary center occurred through a rare cross‐coupling reaction of a tertiary organometallic complex. 1,1‐Arylboration was enabled by catalyst optimization and occurred through a β‐hydride elimination/reinsertion cascade. Enantioselective variants of both processes are presented as well as mechanistic investigations.     

The preparation of 3‐substituted 1,2‐benzisothiazole‐1,1‐dioxides from the condensation‐cyclization of dilithiated β‐ketoesters with methyl 2‐(aminosulfonyl)benzoate or 1,2‐benzisothiazol‐3(2H)‐one‐1,1‐dioxide

Several β‐ketoesters were dilithiated with an excess of lithium diisopropylamide, followed by condensation with methyl 2‐(aminosulfonyl)benzoate to give intermediates that were not isolated but cyclized to 3‐substituted 1,2‐benzisothiazole‐1,1‐dioxides. In most instances involving the ester‐sulfonamide, a single β‐ketoester tautomer is usually formed after recrystallization from ethanol. The same dilithiated β‐ketoesters generally condense less well with 1,2‐benzisothiazol‐3(2H)‐one‐1,1‐dioxide (saccharin) under the same conditions to afford the same products usually in the same or lower yields. The use of N,N,N',N'‐tetramethylethylenediamine during these syntheses has sometimes resulted in improved yields of products.     

Trichloro(1,1‐dimethylbiguanidium‐κN3)zinc(II)

The title compound, [ZnCl₃(C₄H₁₂N₅)], was prepared from aqueous solution and its structure determined. The coordination geometry around the Zn atom is a tetrahedron, with the central Zn atom bound to three Cl atoms and to one N atom of the biguanide ligand. The dihedral angle between the two guanidine groups is 67.86 (1)°.     

1,1′‐Nitramino‐5,5′‐bitetrazoles

1,1′‐Dinitramino‐5,5′‐bitetrazole and 1,1′‐dinitramino‐5,5′‐azobitetrazole were synthesized for the first time. The neutral compounds are extremely sensitive and powerful explosives. Selected nitrogen‐rich salts were prepared to adjust sensitivity and performance values. The compounds were characterized by low‐temperature X‐ray diffraction, IR and Raman spectroscopy, multinuclear NMR spectroscopy, elemental analysis, and DTA/DSC. Calculated energetic performances using the EXPLO5 code based on calculated (CBS‐4M) heats of formation and X‐ray densities support the high performances of the 1,1′‐dinitramino‐5,5′‐bitetrazoles as energetic materials. The sensitivities toward impact, friction, and electrostatic discharge were also explored. Most of the compounds show sensitivities in the range of primary explosives and should only be handled with great care!     

Facile synthesis of 1, 2‐benzisothiazole‐3‐one‐1,1 ‐dioxide methylsulfonyl derivatives

An improved and general synthesis of saccharin methylthio and methylsulfone derivatives from chlorosubstituted saccharins is presented. A large‐scale procedure for preparation of chloro‐substituted saccharins was developed. Treatment of the saccharin chlorides with sodium thiomethoxide and t‐BuOK in DMF gave the saccharin methyl sulfides, which upon chromium(VI) oxide catalyzed oxidation with periodic acid afforded the corresponding saccharin methylsulfones in high yields.     

N,N′‐Bis(2‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide and N,N′‐bis­(3‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide

The mol­ecules of N,N′‐bis­(2‐pyridylmeth­yl)ferrocene‐1,1′‐diyl­dicarboxamide, [Fe(C₁₂H₁₁N₂O)₂], contain intra­molecular N—H⋯N hydrogen bonds and are linked into sheets by three independent C—H⋯O hydrogen bonds. The mol­ecules of the isomeric compound N,N′‐bis­(3‐pyridylmeth­yl)ferrocene‐1,1′‐diyldicarboxamide lie across inversion centres, and the mol­ecules are linked into sheets by a combination of N—H⋯N hydrogen bonds and π–π stacking inter­actions between pyridyl groups.     

An improved procedure for the synthesis of 4,4‐disubstituted‐3‐oxo‐1,2,5‐thiadiazolidine 1,1 ‐dioxides

An improved synthesis for the preparation of 3‐oxo‐1,2,5‐thiadiazolidine 1,1‐dioxides has been developed. This facile two‐step procedure fromα‐amino acid esters and chlorosulfonyl isocyanate results in excellent yields of products.