the dioxolane ring had a small effect on the asymmetric induction by DIOP in the hydrogenation. Modification at the phosphino group affected the stereocontrol by the ligand and the unsymmetrical DIOP with di-2-naphthylphosphino group gave higher optical yields than (−)-DIOP for the hydrogenation of α-acetamidocinnamic acid and dehydrodipeptides.
ETHYLENE TETRAMERIZATION CATALYST SYSTEMS AND METHOD FOR PREPARING 1-OCTENE USING THE SAME
申请人:Han Taek Kyu
公开号:US20100137669A1
公开(公告)日:2010-06-03
Disclosed herein is a method of preparing 1-octene at high activity and high selectivity while stably maintaining reaction activity by tetramerizing ethylene using a chromium-based catalyst system comprising a transition metal or a transition metal precursor, a cocatalyst, and a P—C—C—P backbone structure ligand represented by (R
1
)(R
2
)P—(R
5
)CHCH(R
6
)—P(R
3
)(R
4
).
Ethylene oligomerization catalyst systems having enhanced selectivity
申请人:SK Innovation Co., Ltd.
公开号:US08309779B2
公开(公告)日:2012-11-13
Disclosed herein is a catalyst system for selective oligomerization of ethylene, which comprises a P—C—C—P frame-work ligand, which is (R1)(R2)P—(R5)CHCH(R6)—P(R3)(R4), and a chromium-based metal compound. Also disclosed is a method of greatly enhancing the activity and selectivity of oligomerization, such as trimerization or tetramerization, using a ligand having a specific steric arrangement structure.
Asymmetric Hydrosilylation of Cyclopentadiene and Styrene with Chlorosilanes Catalyzed by Palladium Complexes of Chiral (β-<i>N</i>-Sulfonylaminoalkyl)phosphines
作者:Toshimi Okada、Toshiaki Morimoto、Kazuo Achiwa
DOI:10.1246/cl.1990.999
日期:1990.6
It was found that the palladiumcomplexes of newly prepared chiral (β-aminoalkyl)phosphine derivatives bearing N-sulfonyl groups were efficient catalysts for asymmetric hydrosilylations of cyclopentadiene and styrene with chlorosilanes.
Synthesis of Poly(3-hexylthiophene) by Using the VO(acac)<sub>2</sub>-FeCl<sub>3</sub>-O<sub>2</sub>Catalytic System
作者:Shuyan Yu、Teruaki Hayakawa、Mitsuru Ueda
DOI:10.1246/cl.1999.559
日期:1999.7
Poly(3-hexylthiophene) (P3HT) was prepared by the oxidation coupling polymerization of 3-hexylthiophene (3HT) with molecular oxygen as an oxidant in the presence of vanadyl acetylacetonate (IV) (VO(acac)2) and ferric chloride (FeCl3). The polymerization at a molar ratio of VO(acac)2 / FeCl3 / 3HT = 1 / 2 / 5 in 1,2-dichloroethane at 0 °C for 164 h under oxygen gave P3HT in 61% yield. The resulting polymer gave a number average molecular weight (Mn) of 2.1 × 104 (Mw / Mn = 3.0; Mw: weight average molecular weight) and a head-to-tail content of 65%. The VO(acac)2-FeCl3 complex is supposed to work as a catalyst.