Aryl–secondary alkyl cross-coupling with aryl sulfonate esters as coupling partners remains a significant challenge. Efficient cross-coupling between aryl/alkenyl triflates and acyclicsecondary alkylboronic acids is realized for the first time to provide a series of sterically congested acyclicsecondary alkyl arenes/olefins in good to excellent yields. The employment of sterically bulky P,PO ligand L1/L2 is
NOVEL SPIRO COMPOUND AND MEDICINE COMPRISING THE SAME
申请人:Nakashima Hisashi
公开号:US20100022572A1
公开(公告)日:2010-01-28
It is to provide a novel compound useful for preventing and/or treating diabetes, insulin resistance, diabetes complication, obesity, dyslipidemia, hypertension, fatty liver, or metabolic syndrome.
A spiro compound represented by the following general formula (1) or salt thereof, or their solvate.
<i>C</i><sub>1</sub>-Symmetric Si-bridged (2-indenyl)(1-indenyl) <i>ansa</i>-metallocenes as efficient ethene/1-hexene copolymerization catalysts
作者:Dmitry V. Uborsky、Dmitry Y. Mladentsev、Bogdan A. Guzeev、Ilya S. Borisov、Antonio Vittoria、Christian Ehm、Roberta Cipullo、Coen Hendriksen、Nic Friederichs、Vincenzo Busico、Alexander Z. Voskoboynikov
DOI:10.1039/c9dt04896k
日期:——
Synthesis, ethene/1-hexene copolymerization screening, and QSAR study of 28 silicon bridged (2-indenyl)(1-indenyl) zirconocenes: new promising catalysts for LLDPE were identified.
Synthesis and characterization of new bis(2-R-indenyl) zirconium dichloride complexes for the olefin polymerization
作者:Gong Yeal Lee、Ming Xue、Myoung Soon Kang、Oh Chul Kwon、Jin-San Yoon、Yoo-Su Lee、Hoon Sik Kim、Hyunjoo Lee、Ik-Mo Lee
DOI:10.1016/s0022-328x(98)00386-6
日期:1998.5
corresponding alkyl anions to 2-indanone in the presence (or absence) of LaCl3. With these 2-alkylindenes, bis(2-alkylindenyl)zirconium dichloride complexes were synthesized to investigate the effects of alkyl substituents at 2-position of indene on the rotational conversion rate between rotamers (racemic and meso) and the catalytic activities toward olefin polymerization. Analysis of NMR spectra could line
Polyolefin production catalyst and method of preparing polyolefins
申请人:Japan Polyolafins Co., Ltd.
公开号:US06121182A1
公开(公告)日:2000-09-19
A catalyst component for polyolefin production catalysts comprising a metallocene compound represented by general formula (1) (symbols have the meanings as described in the specification), polyolefin production catalyst containing the component, and method for producing polyolefin with the catalyst are provided. Use of a catalyst containing the novel metallocene compound as a catalyst component of the invention in polymerization of .alpha.-olefin, particularly propylene, enables one to prepare high rigid, high melting point isotactic polypropylene useful as an industrial material for automobiles and the like, more specifically isotactic polypropylene having highly controlled stereoregulartity and regioregularity, particularly the one having a high regioregularity that has been difficult to achieve with conventional metallocene catalysts. ##STR1##