Free Radical-mediated Hydroxymethylation Using CO and HCHO

Tin-free radical hydroxymethylations of haloalkanes using CO and HCHO as a C1 unit proceed efficiently in the presence of borohydrides as radical mediators. In the approach using CO, the formation of aldehydes by radical carbonylation and their subsequent reduction by hydrides lead to alcohols. On the other hand, the use of formaldehyde is more straightforward, in which the key reaction is alkyl radical addition to formaldehyde to give alkoxy radical, which abstracts hydrogen from borohydride reagents. The cascade sequences were observed in the reaction of cholesteryl bromide with HCHO, which displays the diverse applications of HCHO in radical chemistry

C-C Bond Forming Reactions Using Borohydride Reagents as Radical Mediators

学位記番号：論理第107号, 指導教員：柳 日

Essays on technology, investment, and business cycles.

This dissertation is a theoretical and empirical examination of macroeconomic fluctuations. In particular, it focuses on understanding the short- and medium-run effects of changes in technology, developing propagation mechanisms in business-cycle models, and considering the implications of imperfect competition for the behavior of business fixed investment. In Chapter I, I develop a quantitative, general-equilibrium business cycle model with imperfect common knowledge regarding technology shocks. I show that the model has the ability to explain the short-run contractionary effects of technology improvements. In particular, the model predicts that a positive technology shock leads to a persistent decline in employment and a delayed, sluggish fall in inflation. Using the model, I also examine the role of monetary policy in stabilizing macroeconomic fluctuations originating from technology shocks. I then find that monetary policy tends to fall short of accommodation of technology improvements when the central bank has only imperfect information on the state of the technology. In Chapter II, I attempt to construct a measure of true aggregate technical change for the Japanese economy over 1973--1998, controlling for imperfect competition, cyclical utilization of capital and labor, and reallocation effects. I then find little evidence of a decline in the pace of technological progress during the 1990s. Both cyclical utilization and reallocations of inputs across industries appear to have played an important role in lowering measured productivity growth relative to true technology growth. My results thus cast doubt on an explanation of Japan's lost decade that attributes the prolonged slump to the observed productivity slowdown. In Chapter III, I propose a new method for empirical implementation of the Q-theory for investment. In particular, by solving a firm's dynamic cost minimization problem under fairly general conditions, I derive the Q-theory Euler equation that is robust to a large variety of phenomena such as imperfect competition, increasing returns to scale, sticky output prices, and cyclical fluctuations in the markup. Using data on U.S. manufacturing industries, I then find that my new empirical Euler equation for investment helps in providing a remedy for the poor empirical performance of the Q-theory.Ph.D.Economic theoryEconomicsSocial SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/124093/2/3121961.pd

Does information technology raise Japan's productivity?

A standard growth accounting exercise indicates that, after Japan's "lost decade," its overall total-factor-productivity (TFP) growth has increased notably since 2000. This productivity revival has been limited, however, to information technology (IT) production--has not been a broad-based productivity acceleration like that seen in the United States after the mid-1990s. This paper examines the relationship between IT and productivity gains by employing the "augmented" growth accounting framework for Japanese industry-level data from 1975 through 2005. In particular, we estimate "purified" technology change at industry level by accounting for cyclical mismeasurement of inputs. We find that the post-2000 increase in overall TFP growth does indeed appear to arise from an increase in technological change. Furthermore, the pickup in technology growth has occurred not only in the production of IT but also in the industries that use IT intensively. Our results suggest the possibility that stories of IT as a general purpose technology (GPT) could apply to Japan as well as to the United States.Total factor productivity; Information technology; Japanese economy;

Synthesis of 1-(1-Arylvinyl)pyridin-2(1H)-ones from Ketones and 2-Fluoropyridine

Pyridone skeletons are found in numerous biologically active molecules and pharmaceuticals. 1-(1-Arylvinyl)pyridin-2(1H)-ones are synthetic intermediates derived from the enamide moiety, and only few examples of the synthesis of 1-(1-arylvinyl)-2-pyridones have been reported. In this work, a simple and efficient procedure for the synthesis of N-vinyl-substituted pyridones from ketones and 2-fluoropyridine in the presence of trifluoromethane sulfonic anhydride, followed by base treatment is described. Various ketones with electron-donating or -withdrawing groups at the benzene rings can be used in this reaction. A preliminary mechanistic study indicates that it is not very likely that both vinyl triflates and vinyl cations play major roles as intermediates in this transformation. The thus obtained pyridones can be subsequently transformed via C–H arylation and radical alkylation reactions

Estimation of the rate constants for the radical addition of a trifluoromethyl radical to aryl-substituted vinyl triflates

The rate constants for the radical addition of a trifluoromethyl radical to aryl-substituted vinyl triflates have been determined by applying competition kinetics at a single concentration point. The rate constants range from 4.1 × 106 to 5.6 × 106 M−1 s−1 and depend on the electronic properties of the benzene rings on the aryl-substituted vinyl triflates

Flow Giese reaction using cyanoborohydride as a radical mediator

Tin-free Giese reactions, employing primary, secondary, and tertiary alkyl iodides as radical precursors, ethyl acrylate as a radical trap, and sodium cyanoborohydride as a radical mediator, were examined in a continuous flow system. With the use of an automated flow microreactor, flow reaction conditions for the Giese reaction were quickly optimized, and it was found that a reaction temperature of 70 °C in combination with a residence time of 10–15 minutes gave good yields of the desired addition products

Development of a Strain Evaluation Technique Using a Micro Focus X-ray Beam

A strain evaluation technique using a micro focus X-ray beam was developed. An electron gun with two electron lenses was used in order to steadily make a fine focus of an electron beam on a copper target. A target current was 24 mA, and an X-ray brightness 162 Â 10 9 W/m 2 was obtained. X-ray beam was condensed to a converging angle 0.09 deg with a convergent unit, and the minimum focus diameter was 60 mm. A Cu-K 2 's peak can be easily split from a K 1 's peak, because the converging angle of the X-ray beam is low and an X-ray brightness is high. A charge coupled device camera can be set in order to observe the irradiated area on a sample. A cubic ZrO 2 -10 mol%Y 2 O 3 single crystal cut along a (001) plane was selected as a sample to ensure a measurement technique. The difference in a Miller index from an integer was less than 0.4%. A lattice parameter of the specimen was 0:51442 AE 0:00002 nm, and the reference value was 0.5144 nm. Strain was loaded to the sample with a four-point bending jig. A strain tensor was analyzed from the difference in the lattice parameters which were calculated using from 15 to 50 planes. Although the some measured values had a more than 100 Â 10 À6 difference from the estimated ones, the other measured values were almost same as the estimated ones within experimental error

Cyanoborohydride-Promoted Radical Arylation of Benzene

Radical biaryl coupling of iodoarenes and benzene can be effectively promoted by tetrabutylammonium cyanoborohydride with air under photoirradiation conditions using a Xe lamp. The utility of this methodology is highlighted by its functional group tolerance and chemoselectivity