A series of 3-halo-5-phenyl- and 3-phenyl-5-haloisoxazoles has demonstrated anthelmintic activity at doses ranging from 16 to 500 mg/kg orally against the rat roundworm, Nippostrongylus braziliensis. In the 5-phenyl series a halogen at the 3 position of the isoxazole ring was required for activity. However, in the 3-phenyl series activity was maintained after replacement of the 5-halogen with certain alkoxyl, thioalkoxyl, or amino groups. The 3-phenyl and 5-phenyl series apparently are not acting biologically at a common receptor site. Synthetic methods and structure-activity relationships are discussed.
6‐bis(oxazoline) (pybox) ligands for asymmetric transition metal catalysis is introduced by adding a bidentate ligand to modulate the electronic properties and asymmetric induction. Specifically, a ruthenium(II) pybox fragment is combined with a cyclometalated N‐heterocyclic carbene (NHC) ligand to generate catalysts for enantioselective transition metal nitrenoid chemistry, including ring contraction
通过添加双齿配体来调节电子性质和不对称诱导,提出了扩大手性吡啶-2,6-双(恶唑啉)(pybox)配体在不对称过渡金属催化中的应用的策略。具体来说,钌 (II) pybox 片段与环金属化 N-杂环卡宾 (NHC) 配体结合,生成用于对映选择性过渡金属氮烯化学的催化剂,包括环收缩为手性 2H-氮丙啶(2000 TON 时高达 97% ee)和对映选择性 C(sp 3 )−H 胺化(50 TON 时高达 97 % ee)。
Isoxazole anthelmintics
作者:John B. Carr、Harry G. Durham、D. Kendall Hass
DOI:10.1021/jm00217a014
日期:1977.7
A series of 3-halo-5-phenyl- and 3-phenyl-5-haloisoxazoles has demonstrated anthelmintic activity at doses ranging from 16 to 500 mg/kg orally against the rat roundworm, Nippostrongylus braziliensis. In the 5-phenyl series a halogen at the 3 position of the isoxazole ring was required for activity. However, in the 3-phenyl series activity was maintained after replacement of the 5-halogen with certain alkoxyl, thioalkoxyl, or amino groups. The 3-phenyl and 5-phenyl series apparently are not acting biologically at a common receptor site. Synthetic methods and structure-activity relationships are discussed.