This review focuses on the recent development of efficient, selective, and cheaper hydrosilylation catalyst systems appearing in last decade.

Direct borylation of C-H bonds in aromatic compounds can be achieved by using the efficient homogeneous catalyst precursor [RhCl(PiPr3 )2 (N2 )] and pinacolborane (HBpin; see scheme). High selectivity for benzyl positions, observed toluene, p-xylene, mesitylene, was attributed to formation η3 -benzyl intermediates.

The cheap nickel catalysts are more reactive than the corresponding noble metal in catalytic additions of a variety P(O)-H bonds and an S-H bond to alkynes, affording regio- stereoselectively both Markovnikov anti-Markovnikov adducts, respectively, high yields. A related five-coordinate hydrido complex catalysis is successfully isolated, which can react readily with alkyne give addition products.

Mixed-acid systems consisting of both Lewis and Brønsted acids were found to be efficient catalysts for direct synthesis methyl levulinate from cellulose.

A Pd-catalyzed dehydrogenative phosphorylation of thiols is developed. variety dehydrogenatively couple readily with all three kinds P(O)–H compounds, i.e., H-phosphonates, H-phosphinates, and secondary phosphine oxides, providing a general access to the valuable phosphorothioates including P-chiral compounds. plausible mechanism proposed.

cis addition of the borylstannanes Me3SnB[NMe(CH2CH2)NMe] (1) and Me3SnB(NEt2)2 (4) across alkynes was efficiently catalyzed at room temperature or 80 °C by Pd(PPh3)4, Pd(dba)2, Cl2Pd(PPh3)2, Me2Pd[PMe2(CH2CH2)PMe2] to give (β-stannylalkenyl)boranes in high yields. Treatments 1 with 4 cis-Me2Pd(PPh2Me)2 gave [{MeN(CH2CH2)MeN}B](Me3Sn)Pd[PMe2(CH2CH2)PMe2] (5) [(Et2N)2B](Me3Sn)Pd(PPh2Me)2 (6), respectively, former characterized X-ray analysis. Complex 5, when treated 1-octyne, formed...

Keeping the lid on CO2: Atmospheric CO2 can be trapped irreversibly by hypervalent organobismuth oxide and hydroxide compounds, while an analogous alkoxide binds this greenhouse gas reversibly (see scheme). The nature of bismuth compounds is shown to play a decisive roll in these reactions. Supporting information for article available WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z802277_s.pdf or from author. Please note: publisher not responsible content functionality any...

Abstract A series of iridium tetrahydride complexes [Ir(H) 4 (PSiP‐R)] bearing a tridentate pincer‐type bis(phosphino)silyl ligand ([{2‐(R 2 P)C 6 H } MeSi] − , PSiP‐R, R=Cy, i Pr, or t Bu) were synthesized by the reduction [IrCl(H)(PSiP‐R)] with Me N ⋅ BH under argon. The same reaction nitrogen atmosphere afforded rare example thermally stable iridium(III)–dinitrogen complexes, (N )(PSiP‐R)]. Two isomeric dinitrogen produced, in which PSiP coordinated to center meridional and facial...

Organocatalytic controlled/living ring-opening polymerization of cyclotrisiloxanes using water as an initiator and strong organic bases catalysts produced a variety linear polysiloxanes with narrow polydispersity well-defined symmetric structures.

Olefin hydrosilylation was attained at room temperature 0.5 mol% Ni loading by using a series of (salicylaldiminato)methylnickel complexes as catalyst precursors.

A nickel complex/Lewis acid combination effectively catalyzed the direct silyl–Heck reaction of chlorosilanes, which are key raw materials in organosilicon industry, to give synthetically important alkenylsilane products. Trichlorosilanes, dichlorosilanes, and monochlorosilanes underwent afford corresponding alkenylsilanes high yields. In reactions a single substitution occurred monoalkenylsilanes highly selective manner.

Formally hexavalent palladium complexes have been isolated and structurally characterized for the first time. Thermal condensation reaction of three molecules 1,2-C6H4(SiH2)2PdII(R2PCH2CH2PR2) (where R is defined as a methyl or ethyl) provided trinuclear complexes. Single-crystal x-ray analysis revealed that each central atoms ligated by six silicon hexavalent, whereas other are divalent.

The reaction mechanism of the rhodium-phosphine catalysed borylation methyl-substituted arenes using pinacolborane (HBpin) has been investigated theoretically DFT calculations at B3PW91 level. Factors affecting selectivity for benzylic vs. aromatic C-H bond activation have examined. It was found that [Rh(PR3)2(H)] is active species which oxidatively adds leading to an eta3-benzyl complex key determining unusual regioselectivity observed experimentally this catalyst system. Subsequent with...

Rhodium hydrido boryl complexes of the form [(PR3)2RhHCl{B(OR')2}] are key first intermediates in several Rh-catalyzed borylation processes. Previous theoretical studies have examined model compounds, e.g with PH3 and BH2 or B(OH)2 groups, there were little structural data available for this class compounds to compare calculated structures. This paper reports results single-crystal X-ray (at 120 K) neutron 20 diffraction on two such complexes, namely [(PiPr3)2RhHCl(Bpin)] (3Bpin)...

An on-chip 1-Mb SRAM suitable for embedding in the application processor used mobile cellular phones was developed. This supports three operating modes - high-speed active mode, low-leakage low-speed and standby mode uses a subdivisional power-line control (SPC) scheme. The combination of SPC scheme realizes low-power operation under actual usage conditions. It operates at 300 MHz, with leakage 25 /spl mu/A/Mb 50 mode. also self-bias write that decreases minimum voltage by about 100 mV.

Die direkte Borylierung von C-H-Bindungen in Arenen wird mit der effizienten Katalysatorvorstufe [RhCl(PiPr3)2(N2)] und Pinakolboran (HBpin) erreicht (siehe Schema). hohe Selektivität für Benzylpositionen, die Toluol, p-Xylol Mesitylen beobachtet wurde, Bildung η3-Benzylintermediaten zugeschrieben. Supporting information for this article is available on the WWW under http://www.angewandte.com or from author. Please note: The publisher not responsible content functionality of any supporting...

The power consumption of a low-power system-on-a-chip (SoC) has large impact on the battery life mobile appliances. General SoCs have on-chip SRAMs, which consume proportion whole LSI power. To achieve SoC, we developed embedded SRAM modules, use some techniques. One technique involves expanding write margin; another is power-line-floating technique, enables low-voltage operation. makes it possible to lower minimum operating supply voltage by 100 mV. other techniques involve using...

Two bismuth compounds bearing a sulfur-bridged bis(phenolato) ligand were synthesized and found to show high catalytic activity selectivity for solvent-free synthesis of propylene carbonate from CO(2) oxide in the presence iodide salts as co-catalysts at room temperature under 1 atm CO(2).

Abstract Application of photo-aryl coupling reactions for the syntheses triphenylene and dibenzo[fg,op]naphthacene was explored. Three types were developed: Photocyclodehydrogenation polyphenyl compounds, photolytic iodoarenes, photocyclodehydrohalogenation halogenopolyaryls. The effects solvent, oxidant, wavelength on photocyclization o-terphenyl 2,2′-diphenylbiphenyl to naphthacene, respectively, examined. conversion best achieved by reaction carried out in an aromatic solvent presence...

We report a highly selective synthesis of siloxane building blocks containing SiH2 or SiH functionalities. AuCl(PPh3)/PPh3 AuCl(PPh3)/PnBu3 system catalyzed the reaction trihydrosilanes with silanols giving SiH2-containing siloxanes exclusively. On other hand, dihydrosilanes to afford SiH-containing was achieved by simply changing phosphine ligand bidentate one, xantphos. Usefulness demonstrated trisiloxane, Et3SiOSi(Ph)(H)OSitBuMe2, and pentasiloxane, Ph2Si(OSiHPhOSiEt3)2, bearing

Hypervalent organobismuth compounds efficiently couple with aryl bromides in the presence of [Pd(PPh3)4] catalyst. Application this protocol to a one-pot multicoupling reaction bromophenylboronic esters leads formation up nine bonds good yields (see scheme).

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUnusual Reactivity of 1,2-Disilylbenzene toward Pt(0) Complexes. Isolation the First PtIVSi4P2 and Dinuclear, Mixed-Valence PtIIPtIVSi4P4 ComplexesShigeru Shimada, Masato Tanaka, Kazumasa HondaCite this: J. Am. Chem. Soc. 1995, 117, 31, 8289–8290Publication Date (Print):August 1, 1995Publication History Published online1 May 2002Published inissue 1 August...