Efficient Synthesis of Enantiomerically Pure β<sup>2</sup>-Amino Acids via Chiral Isoxazolidinones
作者:Hee-Seung Lee、Jin-Seong Park、Byeong Moon Kim、Samuel H. Gellman
DOI:10.1021/jo026738b
日期:2003.2.1
We report a practical and scalable synthetic route for the preparation of alpha-substituted beta-amino acids (beta(2)-amino acids). Michael addition of a chiral hydroxylamine, derived from alpha-methylbenzylamine, to an alpha-alkylacrylate followed by cyclization gives a diastereomeric mixture of alpha-substituted isoxazolidinones. These diastereomers are separable by column chromatography. Subsequent
Alkylation of Allyl/Alkenyl Sulfones by Deoxygenation of Alkoxyl Radicals
作者:Jia-Bin Han、Ao Guo、Xiang-Ying Tang
DOI:10.1002/chem.201806138
日期:2019.2.26
challenging deoxygenation of alkoxyl radicals from readily accessible alcohol derivatives was developed, affording facile synthesis of functionalized alkenes with good functional group tolerance under mild reaction conditions. Because alkoxyl radicals can easily undergo β‐fragmentations or hydrogen abstractions, this new strategy for deoxygenation of alkoxyl radicals is highly valuable. Moreover, mechanistic
Building blocks of the general type FmocXaaΨPO(OAd)CH2}YaaOH suitable for solid-phase synthesis of phosphinic peptides have been prepared using a new synthetic strategy based on mild and high-yielding reactions. The key reaction of this method is the Michaeladdition of activated Fmoc protected silyl aminophosphonites to benzyl acrylates at room temperature. As compared to our previous work, this
The invention relates compounds of the formula ##STR1## wherein R.sup.1 -R.sup.5 and X have the significance given in the description, and their pharmaceutically acceptable salts. The compounds of formula I inhibit the enzyme collagenase and can be used in the form of medicaments for the control or prevention of degenerative joint diseases such as rheumatoid arthritis and osteoarthritis.
Dispersion composition, curable composition using the same, transparent film, microlens, and solid-state imaging device
申请人:Arayama Kyouhei
公开号:US10287422B2
公开(公告)日:2019-05-14
There is provided a dispersion composition capable of forming a film being excellent in surface conditions, the dispersion composition containing metal oxide particles (A) having a primary particle diameter of 1 nm to 100 nm, a polymer compound (B) having an acid value of less than 120 mgKOH/g, which is represented by the following Formula (1), and a solvent (C).