Exclusive <i>α</i>-Coupling in the Aldol Reaction of Unsaturated Trimethylsilyl Esters: An Efficient and Practical Direct Synthesis of Unsaturated <i>β</i>-Hydroxy Acids
give exclusively the alpha-condensation products in excellent yields. The unsaturated beta-hydroxy acids thus obtained were directly identified, and the usual conversion into their methyl esters with diazomethane was not necessary. Unsaturated ketones underwent Michael reaction through alpha-addition leading to the unsaturated 5-oxo acids.
Synthesis and CO<sub>2</sub> Insertion Reactivity of Allyluranium Metallocene Complexes
作者:Christopher L. Webster、Joseph W. Ziller、William J. Evans
DOI:10.1021/om3007536
日期:2012.10.22
and η1-allyl ligands: (C5Me5)2U[η3-CH2C(R)CH2][η1-CH2C(R)═CH2]. Sodium amalgam reduction of (C5Me5)2U[η3-CH2C(R)CH2]Cl generates the U3+ metallocene allyl complexes (C5Me5)2U[η3-CH2C(R)CH2]. Carbon dioxide reacts with the U4+ allyl complexes to form the U–C insertion products (C5Me5)2U[κ2O,O′-O2CCH2CH═CH2]2–xClx (x = 0, 1). The dicarboxylate (C5Me5)2U[κ2O,O′-O2CCH2CH═CH2]2, which has a 171.98(5)° O–U–O
There is provided herein an extended longevity fragrance delivery composition which includes (a) acid-functional silicone, (b) fragrance, and; (c) water and/or organic solvent and, optionally, (d) at least one emulsifier or suspending agent, wherein acid-functional silicone (a) is present in a fragrance longevity-enhancing amount. There is also provided a process of making the fragrance delivery composition comprising combining (a)-(c) and optionally (d), applying the aqueous emulsion or suspension on a hair, skin, fabric or hard surface, and allowing the film to dry to form an ionically crosslinked film or residue which entraps the fragrance providing for long term fragrance effect to the hair, skin, fabric or hard surface.
Polymer electrolyte as well as polymer electrolyte membrane, membrane electrode assembly and polymer electrolyte fuel cell using the same
申请人:Nakamura Masataka
公开号:US20070134530A1
公开(公告)日:2007-06-14
The present invention relates to a polymer electrolyte that provides high proton conductivity and low fuel crossover at the same time, as well as a member using the same. The embodiments of the invention can achieve high output and high energy density in the form of a polymer electrolyte fuel cell. A polymer electrolyte comprising a proton conductive polymer (A) and a polymer (B) which is different from (A) wherein a ratio of the amount of unfreezable water, represented by formula (S1), in said polymer electrolyte is no less than 40 wt % and no greater than 100 wt % is disclosed. The ratio of amount of unfreezable water (S1)=(amount of unfreezable water)/(amount of low melting point water+amount of unfreezable water)×100 (%).