Facile Preparation of Benzylic Iodides Under Solvent‐Free Conditions Using Microwave Irradiation

Abstract

Benzylic alcohols are rapidly converted to the corresponding benzylic iodides using combination of p‐toluenesulfonic acid (PTSA) and potassium iodide under solvent‐free microwave irradiation conditions.     

RbYbI_3晶体结构的精化

用Ｘ射线粉末法确定了ＲｂＹｂＩ３的晶体结构，并用Ｒｉｅｔｖｅｌｄ技术精化了结构。晶体结构属于正交晶系，ａ＝１０３８３（３）ｎｍ，ｂ＝０４６６７（１）ｎｍ，ｃ＝１７２００（５）ｎｍ，空间群为Ｐｎｍａ（６２），Ｚ＝４，所有原子均占据空间群Ｐｎｍａ的４ｃ位置。Ｙｂ原子被Ｉ原子配位形成畸变的八面体，这些八面体共棱连接形成沿ｂ轴的双链是ＲｂＹｂＩ３晶体结构的特征。     

Crystal Structure of Rubidium Tetraiodothallate(III) Dihydrate,RbTlI4·2H2O

The crystal structure of RbTlI₄·2H₂O (cubic, , Nr. 226, Z = 24, a = 1993.5(2) pm, 327 unique reflections with I_o > 2σ(I_o), R₁ = 0.0305, wR₂ = 0.0702, GooF = 1.1199, T = 298(2) K) is characterized by an ReO₃ analogous arrangement of rubidium centered [TlI₄] tetrahedra. The cuboctahedral cavities of this structure are filled with crystal water molecules and additional disordered rubidium cations.     

Action of Alkaline Earth Metals on Lanthanum Triiodide: Unusually Short La‐La Distances in SrLaI4 and BaLaI4

Black single crystals with metallic lustre of SrLaI₄ and BaLaI₄ were obtained by reduction of lanthanum triiodide, LaI₃, with strontium and barium, respectively, in sealed tantalum containers at 800 °C or above. The crystal structure was determined from X‐ray diffraction intensities; SrLaI₄ and BaLaI₄ are isotypic and crystallize with the monoclinic crystal system (space group I2/a, Z = 4, for SrLaI₄: a = 742.3(1), b = 1485.2(3), c = 862.3(1) pm, β = 101.07(2)°). The lanthanum atoms are in an eightfold square antiprismatic coordination with La‐I distances of 329—339 pm in SrLaI₄. The [LaI₈] polyhedra are connected via common faces to chains according to [LaI_8/2] running along [100]. This obviously makes exceptionally short La‐La distances of 371 pm possible.     

Synthese und Kristallstrukturen von Ln3I(SiS4)2 (Ln = Pr,Nd, Sm,Tb)

Synthesis and Crystal Structures of Ln₃I(SiS₄)₂ (Ln = Pr, Nd, Sm, Tb) Single crystals of Ln₃I(SiS₄)₂ were prepared by a two‐step reaction of lanthanide metal, sulfur, silicon and iodine in the ratio 1 : 3.25 : 1 : 0.33 in quartz glass tubes. The thiosilicates crystallize in the monoclinic space group C 2/c (Z = 4) isotypic to Ce₃I(SiS₄)₂ [1]. In the crystal structures the iodide ions form chains along [001] with trigonal coordination by lanthanide ions.     

Die Existenz einer Gasphasenspezies BiSeO3I und das Verhalten bei Chemischen Transportreaktionen

The Existence of a Gaseous Species BiSeO₃I and the Behaviour at Chemical Vapour Transports The existence of gaseous species BiSeO₃I follows from chemical vapour transport experiments of BiOI_s with SeO_{2, g} as well as Bi₂SeO_{5, s} with BiI_{3, g} and SeO_{2, g} and Bi₂Se₃O_{9, s} witht BiI_{3, g}. The Enthalpy of formation and the Standardentropy were derived from the quantitative transport rates and the standard data of the solid state and gaseous phases.     

[Ba(Benzo‐15‐Krone‐5)2](In)2: Darstellung und strukturelle Charakterisierung eines Triiodids (n = 3) und eines Heptaiodids (n = 7)

[Ba(benzo‐15‐crown‐5)₂](I₃)₂ and [Ba(benzo‐15‐crown‐5)₂](I₇)₂ can be obtained in crystalline form by reacting benzo‐15‐crown‐5 (C₁₄H₂₀O₅), barium iodide (BaI₂), and iodine (I₂) in ethan‐ole /dichloromethane. The triiodide consists of a sandwich‐like cation [Ba(benzo‐15‐crown‐5)₂]²⁺ and an isolated symmetrically linear I₃^‐ anion. The unusual I₇^‐ anion in the heptaiodide can be described as a V‐shaped pentaiodide unit, which is connected with a slightly widened iodine molecule to the rare Z‐form of the heptaiodide ion. In the crystal structure, secondary bonding distances lead to almost planar ten‐membered iodine rings, which are connected by common edges to form staircase‐like bands.     

Ionic liquid-induced conversion of methoxymethyl-protected alcohols into nitriles and iodides using [Hmim][NO3]

This Letter reports a one-pot efficient conversion of methoxymethyl-ethers into their corresponding nitriles and iodides using the ionic liquid, 1-methyl-3H-imidazolium nitrate ([Hmim][NO₃]) under microwave irradiation. A variety of products were prepared in high yields using this method.     

Rhodium-Catalyzed Anti-Markovnikov Transfer Hydroiodination of Terminal Alkynes**

A rhodium-catalyzed anti-Markovnikov hydroiodination of aromatic and aliphatic terminal alkynes is reported. Depending on the choice of ligand and substrate, either (E)- or (Z)-configured alkenyl iodides are obtained in high to exclusive isomeric purity. The reaction exhibits a broad substrate scope and high functional group tolerance, employing easily accessible or commercially available aliphatic iodides as HI surrogates through a shuttle process. The synthesized vinyl iodides were applied in several C−C and C−heteroatom bond-forming reactions with full retention of the stereoselectivity. The developed method could be used to significantly shorten the total synthesis of a marine cis-fatty acid. Additionally, initial deuterium-labeling experiments and stoichiometric reactions shed some light on the potential reaction mechanism.