In the presence of a catalytic amount of Cp*RuCl(cod), 1,6-diynes were allowed to react chemo- and regioselectively with electron-deficient nitriles and heterocumulenes at 60-90 degrees C to afford heterocyclic compounds. The mechanism of the ruthenium-catalyzed regioselective formations of bicyclic pyridines and pyridones were analyzed on the basis of density functional calculations. Cyclocotrimerizations of ethyl propiolate with ethyl cyanoformate or propyl isocyanate gave rise to two of the four possible pyridine or pyridone regioisomers.

In the presence of catalytic amounts of Cp*Ru(cod)Cl, unsymmetrical 1,6-diynes possessing a variety of functional groups reacted with electron-deficient tricarbonyl compounds at the ketone C=O double bonds to selectively afford dienones via electrocyclic ring opening of the expected alpha-pyrans. The intramolecular Michael addition of the cycloadducts having an acetyl and an alkylidenemalonate moiety gave bicyclo[3.3.0]octenone derivatives.

[reaction: see text] A ruthenium(II) complex possessing a planar Cp ligand, CpRu(cod)Cl, effectively catalyzed the [2 + 2 + 2] cycloaddition of 1,6-diynes with isocyanates to afford bicyclic pyridones in 58-87% yields.

Solution process of silicon will provide high-speed transistor fabrication with low-cost by, for example, roll-to-roll process. In this paper, a low-temperature process (350 C) is reported for fabrication of high-quality Si devices on a polyimide substrate from doctor-blade coated liquid-Si. With this method, different semiconductor devices have been fabricated, reporting a carrier mobility of 460 cm 2 /V s and 121 cm 2 /V s for electrons and holes, respectively. The devices were peeled off and transferred onto a polyethylene naphthalate foil to achieve flexible devices. CMOS inverters were also fabricated and show full output swing. Printed flexible electronics have received considerable attention because of the low-cost and applications in displays, sensors, and radio-frequency identification (RFID) tags on flexible substrates. Organic semiconductors offer a lowtemperature printing process of TFTs on plastic substrates. 1 However, the carrier mobility and reliability are much inferior in comparison with Si devices. Indium Gallium Zinc Oxide (IGZO), as a metal oxide semiconductor, shows higher electron carrier mobility than that of organic semiconductors, but it is impossible to make both PMOS and NMOS TFTs using the same metal oxide. 2 Transferring of CMOS-SOI chips 3 and amorphous Si (a-Si) transistors on plastics by laser release 4 have been reported. However, the former has cost and technical issues since the limited size of the wafer and pick and place process, and in the latter, the electrical performance is low, although the laser release technique requires less cost. Printing of silicon, however, could provide high carrier mobility 5,6 and at the same time the possibility of fabricating NMOS and PMOS TFTs in the same process on a large area substrate. Silicon can be printed using liquid silicon, 5 which is a mixture of ultraviolet (UV)-irradiated cyclopentasilane (CPS) and a solvent. After forming a-Si by sintering spin-coated liquid-Si at 430 C followed by dehydrogenation, poly-Si TFTs 5 and single-grain Si TFTs 6 have been fabricated with excimer-laser crystallization. Although mobilities of the resultant TFTs are much superior to those of organic TFTs, the dehydrogenation process with a temperature of more than 550 C is not suitable for polymeric substrates. In this paper, we report in the fabrication of singlegrain Si TFTs on a polyimide-coated substrate with a maximum process temperature of 350 C using liquid-Si, which was deposited by doctor-blade coating, which is compatible with a roll-to-roll process. The carrier mobility is 460 cm 2 /V s and 121 cm 2 /V s for electrons and holes, respectively. The devices were peeled off and transferred onto a Polyethylene naphthalate (PEN) foil to achieve flexible devices.As shown in Fig. 1, first, a quasi-plastic substrate is prepared with spin-coating 10-lm-thick polyimide layer on top of a supporting crystalline Si substrate, which is subsequently cured at 400 C. Then, by the l-Czochralski process, 7 small indentations called "grain-filters" (100 nm diamet...

In the presence of 10 mol % Cp*Ru(cod)Cl, 1,6-diynes with a tertiary center at 4-position reacted with various isothiocyanates at their C=S double bond to afford bicyclic (2H)-thiopyranimines in 35-88% yields. The (2H)-thiopyran structure was unequivocally determined by X-ray analysis. The cycloaddition of carbon disulfide with a diyne similarly gave the expected bicyclic dithiopyrone in 50% yield.