Manganese-catalyzed homogeneous hydrogenation of ketones and conjugate reduction of α,β-unsaturated carboxylic acid derivatives: A chemoselective, robust, and phosphine-free in situ-protocol
作者:Thomas Vielhaber、Christoph Topf
DOI:10.1016/j.apcata.2021.118280
日期:2021.8
glove-box-free catalytic protocol for the manganese-catalyzed hydrogenation of ketones and conjugated CCbonds of esters and nitriles. The respective catalyst is readily assembled in situ from the privileged [Mn(CO)5Br] precursor and cheap 2-picolylamine. The catalytic transformations were performed in the presence of t-BuOK whereby the corresponding hydrogenation products were obtained in good to excellent yields
我们传达了一种用户友好且无需手套箱的催化协议,用于酮和酯和腈的共轭 C C键的锰催化氢化。相应的催化剂很容易由特权 [Mn(CO) 5 Br] 前体和廉价的 2-吡啶甲胺原位组装。催化转化在t- BuOK存在下进行,从而以良好至极好的收率获得相应的氢化产物。所描述的系统提供了对仲醇和饱和酯的快速和原子效率的访问,避免了使用氧敏感和昂贵的基于膦的配体。
Antioxidants
申请人:Rudolph Thomas
公开号:US20080152603A1
公开(公告)日:2008-06-26
The present invention relates to the use of compounds of the formula (I), with radicals defined in the description, as antioxidants, to corresponding novel compounds and compositions, and to corresponding processes for the preparation of compounds and compositions.
The present invention relates to the use of compounds which do not themselves exhibit significant UV absorption in the UV-A or UV-B region, but are reactive under use conditions, for the development of UV-A or UV-B protection during use, to corresponding novel compounds and compositions, and to corresponding processes for the preparation of compounds and compositions.
characterization, and catalytic application of a triphos-tagged, non-pincer-type tungsten complex. The pertinent W-based half-sandwich compound was used in the homogeneous hydrogenation of ketones and esters to afford the corresponding alcohols. Furthermore, the introduced base metal catalyst facilitated the conjugate reduction of enoates to yield the respective CC-bond-free esters. Most of the applied
我们公开了三磷酸标记的非钳型钨络合物的合成、表征和催化应用。相关的基于 W 的半夹心化合物用于酮和酯的均相氢化以提供相应的醇。此外,引入的贱金属催化剂促进了烯酸酯的共轭还原,从而产生相应的无 C-C 键的酯。大多数应用的底物酮在非常温和的反应条件(室温,5 bar H 2)下在t –BuONa 存在下可转化。辅助碱基中的阳离子从Na +到Li +的交换结果证明对于成功还原羰基酯基团至关重要。部署的有机金属复合物很容易称重,可以在密封手套箱系统外的实验室工作台上处理。
Skin care composition
申请人:DSM IP Assets B.V.
公开号:EP1897530A1
公开(公告)日:2008-03-12
The present invention relates to an oral composition containing an optimal combination of nutritional ingredients at high concentrations and at optimal ratios in order to maintain and/or achieve health and/or beautiful look of the skin.