Synthesis and Structural Characterization of New Zirconium(IV) Bent Metallocenes comprising η8‐Cyclooctatetraenyl and Bulky Cyclopentadienyl Ligands

The new zirconium bent metallocenes (COT)Zr(Cp^tBu2)Cl ( 1 ) and (COT)Zr(Cp′′)Cl ( 2 ) were synthesized in a straightforward manner and in high yields ( 1 : 91 %, 2 : 86 %) by treatment of in situ‐prepared (COT)ZrCl₂(THF) with 1 equiv. of K(Cp^tBu2) or K(Cp′′), respectively (COT = η⁸‐cyclooctatetraenyl; Cp^tBu2 = η⁵‐1,3‐di‐tert‐butylcyclopentadienyl; Cp′′ = η⁵‐1,3‐bis(trimethylsilyl)cyclopentadienyl). Subsequent reaction of 1 with 1 equiv. of phenyllithium afforded the σ‐phenyl derivative (Cp^tBu2)Zr(COT)Ph ( 3 ) as orange crystals in 83 % isolated yield. All three new compounds were structurally characterized through single‐crystal X‐ray diffraction.     

索尼步入复苏期

1999年4月,井原胜美出任索尼手机部门的最高负责人.当时,索尼手机部门的业务跌入谷底,产品销量不佳,连年亏损.     

Hydroxypropylation of Polyphenol-Rich Alkaline Extracts from Pinus radiata Bark and Their Physicochemical Properties

Pinus radiata bark is a rich source of polyphenols, which are mainly composed of proanthocyanidins. This study aimed to utilize P. radiata bark as a polyol source for bio-foam production in the future. Polyphenol-rich alkaline extracts (AEs) from P. radiata bark were prepared by mild alkaline treatment and then derivatized with propylene oxide (PO). Hydroxypropylated alkaline extracts (HAEs) with varying molar substitutions (MS 0.4–8.0) were characterized by FT-IR, NMR, GPC, TGA, and DSC. The hydroxyl value and solubility in commercial polyols were also determined. The molecular weights of the acetylated HAEs (Ac-HAEs) were found to be 4000 to 4900 Da. Analyses of FT-IR of HAEs and ¹H NMR of Ac-HAEs indicated that the aromatic hydroxyl groups were hydroxypropylated and showed an increase in aliphatic hydroxyl group content. The glass transition temperature (T_g) of AE and HAEs were 58 to 60 °C, showing little difference. The hydroxyl value increased as the hydroxypropylation proceeded. Although salts were produced upon neutralization after hydroxypropylation, HAEs still showed suitable solubility in polyether and polyester polyols; HAEs dissolved well in polyether polyol, PEG#400, and solubility reached about 50% (w/w). This indicated that neutralized HAEs could be directly applied to bio-foam production even without removing salts.     

Total synthesis of (+/-)-psychotrimine

new process for the union of anilines with tryptamine derivatives has been developed, furnishing C-3 quaternized pyrroloindoline architectures. This chemoselective coupling of a tryptamine with 1.2 equiv of 2-iodoaniline proceeds efficiently on a gram-scale using only the simple reagents N-iodosuccinimide and triethylamine. Using this new reaction, the complex natural product psychotrimine has been fashioned with a rare level of efficiency and practicality. From a readily available bromotryptamine, only four steps (41-45% overall isolated yield) are necessary to procure gram quantities of the natural product. Functional group manipulations, protecting group chemistry, and unnecessary redox fluctuations have been minimized.