Arylboron compounds have intriguing properties and are important building blocks for chemical synthesis. A family of Ir catalysts now enables the direct synthesis arylboron from aromatic hydrocarbons boranes under "solventless" conditions. The highly selective C-H activation do not interfere with subsequent in situ transformations, including Pd-mediated cross-couplings aryl halides. By virtue their favorable activities exceptional selectivities, these impart synthetic versatility reagents to...

Advancement in hydrogen storage techniques represents one of the most important areas today's materials research. While extensive efforts have been made to existing techniques, there is no viable technology capable meeting DOE cost and performance targets at present time. New with significantly improved adsorption capability are needed. Microporous metal coordination (MMOM) promising candidates for use as sorbents adsorption. These possess physical characteristics similar those single-walled...

Packing them in: Based on zinc and aromatic-rich dicarboxylic acids these new coordination networks (see structure; green Cl, red O, yellow Zn, blue N, gray C) have hydrogen uptakes comparable to those of the best carbon nanotubes metal–organic frameworks. The highly interpenetrating nature points a design strategy for hydrogen-storage materials that employ an entrapment mechanism. Supporting information this article is available WWW under...

With the aid of high-throughput screening, efficiency Ir-catalyzed C-H borylations has been assessed as functions precatalyst, boron reagent, ligand, order addition, temperature, solvent, and substrate. This study not only validated some accepted practices but also uncovered unconventional conditions that were key to substrate performance. We anticipate insights drawn from these findings will be used design reaction for substrates whose are difficult impossible using standard catalytic conditions.

Methane borylation in a cyclohexane sea Although methane combusts readily at high temperatures, it is generally the hardest hydrocarbon to transform under gentler conditions, owing its particularly strong C-H bonds. Cook et al. now show that soluble rhodium, iridium, and ruthenium catalysts can slice through these bonds add boron substituents 150°C. Smith report iridium-catalyzed reaction using phosphine ligands enhance activity. Both studies were performed solvent, revealing remarkable...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTStereoselective Polymerization of a Racemic Monomer with Catalyst: Direct Preparation the Polylactic Acid Stereocomplex from LactideChristopher P. Radano, Gregory L. Baker, and Milton R. SmithView Author Information Department Chemistry, Michigan State University East Lansing, 48824 Cite this: J. Am. Chem. Soc. 2000, 122, 7, 1552–1553Publication Date (Web):February 5, 2000Publication History Received23 August 1999Published online5 February...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSteric and Chelate Directing Effects in Aromatic BorylationJian-Yang Cho, Carl N. Iverson, Milton R. SmithView Author Information Department of Chemistry, Michigan State University East Lansing, 48824 Cite this: J. Am. Chem. Soc. 2000, 122, 51, 12868–12869Publication Date (Web):December 6, 2000Publication History Received14 April 2000Revised18 October 2000Published online6 December inissue 1...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTStoichiometric and Catalytic B−C Bond Formation from Unactivated Hydrocarbons BoranesCarl N. Iverson Milton R. SmithView Author Information Department of Chemistry, Michigan State University East Lansing, 48824 Cite this: J. Am. Chem. Soc. 1999, 121, 33, 7696–7697Publication Date (Web):August 6, 1999Publication History Received20 April 1999Published online6 August inissue 1...

An efficient one-pot C−H activation/borylation/oxidation protocol for the preparation of phenols is described. This method particularly attractive generation meta-substituted bearing ortho-/para-directing groups, as such substrates are difficult to access by other phenol syntheses.

Ir-catalyzed borylation of 2-substituted indoles selectively yields 7-borylated products in good yields. N-Protection, required for previous functionalizations indoles, is unnecessary.

Ir-catalyzed borylations of 4-substituted benzonitriles are described. In contrast to electrophilic aromatic substitutions and directed ortho metalations, C−H activation/borylation enables functionalization at the 2-position, adjacent cyano group, when 4-subsitutent is larger than cyano. When an excess borane reagent used, diborylation can be achieved with a single regioisomer being formed in certain cases. Extension sterically borylation cyano-substituted, five- six-membered ring...

The preparation and reaction chemistry of β-diketiminato aluminum complexes are described. (TTP)AlCl2 (1) (TTPH = 2-(p-tolylamino)-4-(p-tolylimino)-2-pentene) is formed by the treatment AlCl3 with LiTTP. Sequential alkylation 1 CH3Li results in formation mono- dimethyl (TTP)AlMeCl (2) (TTP)AlMe2 (3), respectively. Only monoalkyl produced when more hindered alkyllithium reagents used. Compounds 2 3 conveniently prepared treating Al(CH3)3 TTPH·HCl TTPH, sterically β-diketimine ligand...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReactivity of Organoplatinum Complexes with C6H4O2B-BO2C6H4: Syntheses a Platinum Diboryl Complex with, and without, Metathesis Boron-Boron Metal-Carbon BondsCarl N. Iverson Milton R. Smith IIICite this: J. Am. Chem. Soc. 1995, 117, 15, 4403–4404Publication Date (Print):April 1, 1995Publication History Published online1 May 2002Published inissue 1 April...

Not a trace: Borylation of the nitrogen in heterocycles or anilines provides traceless directing group for subsequent catalytic CH borylation. Selectivities that previously required Boc protection can be achieved; furthermore, NBpin installed and removed situ, product yields are substantially higher. Boc=tert-butoxycarbonyl, pin=pinacolato. As service to our authors readers, this journal supporting information supplied by authors. Such materials peer reviewed may re-organized online...

The NHBoc group affords ortho selective C–H borylations in arenes and alkenes. Experimental computational studies support an outer sphere mechanism where the N–H proton hydrogen bonds to a boryl ligand oxygen. regioselectivities are unique complement those of directed metalations.

"Click" chemistry is a powerful method for post-polymerization modification of polymers and other materials. Because the importance lactide-based functional in materials medical applications, we synthesized 3,6-dipropargyl-1,4-dioxane-2,5-dione, an acetylene-functionalized glycolide monomer. Its subsequent polymerization copolymerization with lactide provided new polyglycolide homopolymer as well random block copolymers that have pendant acetylene groups available attachment chemical...

Ir catalysts supported by bidentate silyl ligands that contain P- or N-donors are shown to effect ortho borylations for a range of substituted aromatics. The substrate scope is broad, and the modular ligand synthesis allows flexible catalyst design.

A strategy for affecting ortho versus meta/para selectivity in Ir-catalyzed C–H borylations (CHBs) of phenols is described. From observations with ArylOBpin (pin = pinacolate), it hypothesized that an electrostatic interaction between the partial negatively charged OBpin group and positively bipyridine ligand catalyst favors selectivity. Experimental computational studies designed to test this hypothesis support it. further work a second generation, silico emerged, where replacing Bpin Beg...

Rare hysteretic adsorption/desorption isotherms are reported for CO2 and N2 on a pillared Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)4] compound (NiBpeneNiCN). The hysteresis occurs under moderate pressure at temperatures above the critical of respective gases. Powder X-ray diffraction measurements indicate that material is an extended three-dimensional analogue well-known Hofmann clathrates which formed through axial bridging in-plane octahedral Ni sites by bidentate 1,2-bis(4-pyridyl)ethylene....

The mechanism of splitting liquid ammonia is investigated to enable its use for renewable hydrogen storage.

Significance Water oxidation fixes carbon dioxide producing ∼100 gigatons (GT) of carbohydrates annually. Living organisms convert the stored chemical energy back to and water through respiration. An analogous cycle can be envisioned whereby hydrogen gas is as ammonia, synthesized from atmospherically ubiquitous dinitrogen. Biological industrial reduction dinitrogen currently estimated produce 0.3–0.5 GT ammonia important reaction in such a proposed nitrogen-based storage distribution scheme...

Para C–H borylations (CHB) of tetraalkylammonium sulfates and sulfamates have been achieved using bipyridine-ligated Ir boryl catalysts. Selectivities can be modulated by both the length alkyl groups in cations substituents on bipyridine ligands. Ion pairing, where cation shield meta bonds counteranions, is proposed to account for para selectivity. The 4,4′-dimethoxy-2,2′-bipyridine ligand gave superior selectivities.

The insertion reactivity of alkynes with the diboryl complex (Ph3P)2Pt(BCat)2 (1, Cat ≡ {C6H4O2}2-) has been investigated. Under stoichiometric conditions 1 mediates cis-diborylation and (PPh3)2Pt fragment is trapped by alkyne to give corresponding Pt−alkyne complexes. Kinetic studies under pseudo first-order indicate that reaction first order in 1. In absence added phosphine, no dependence observed. inhibited phosphine addition, these conditions, a on concentration observed for...

[reaction: see text]. A protocol for performing Rh catalyzed aromatic borylations in cyclohexane has been devised. Borylation at the 5-position of several 1,3-substituted species ranging from electron-rich (1,3-(NMe(2))(2)C(6)H(4)) to electron-deficient (1,3-(CF(3))(2)C(6)H(4)) yields corresponding aryl boronate esters. Veratrole was selectively borylated 4-position, thus extending regioselectivity 1,2-substituted benzenes. Selective borylation 3-position an N-protected pyrrole also...