Nickel-Catalyzed Decarbonyloxidation of 3-Aryl Benzofuran-2(<i>3H</i>)-ones to 2-Hydroxybenzophenones
作者:Zhou Tong、Zhi Tang、Chak-Tong Au、Renhua Qiu
DOI:10.1021/acs.joc.0c00858
日期:2020.7.2
nickel-catalyzed decarbonyloxidation of 3-aryl benzofuran-2(3H)-ones to 2-hydroxybenzophenones under mild conditions, which is an efficient approach for the decarbonyloxidation of lactones in organic synthesis. A diverse range of substrates can undergo C(O)–O/C(O)–C bondcleavage to generate the target products in good yields. These 2-hydroxybenzophenones can be converted into a variety of compounds via reactions
Rhodium‐Catalyzed Spirocyclic Sultam Synthesis by [3+2] Annulation with Cyclic
<i>N</i>
‐Sulfonyl Ketimines and Alkynes
作者:Lin Dong、Chuan‐Hua Qu、Ji‐Rong Huang、Wei Zhang、Qian‐Ru Zhang、Jin‐Gen Deng
DOI:10.1002/chem.201303372
日期:2013.12.2
Atom‐economical addition: RhIII‐catalyzed “Grignard‐type” cyclization between cyclic N‐sulfonyl ketimines and internal alkynes has been developed to afford multifunctional spirocyclic sultam products in high yields (up to 99 %) under mild conditions (see scheme, Cp* = pentamethylcyclopentadienyl, DCE = 1,2‐dichloroethane).
RhIII-catalyzed aryl C–H vinylation for the preparation of styrenes by using vinylacetate, a commercially available and inexpensive compound, as the vinyl source was successfully realized. This method enables various aromatics including N-sulfonyl ketimines, pyridines, azoles, and amides to be vinylated in moderate to good yields.
Nickel‐Catalyzed Asymmetric Hydrogenation of
<i>N</i>
‐Sulfonyl Imines
作者:Bowen Li、Jianzhong Chen、Zhenfeng Zhang、Ilya D. Gridnev、Wanbin Zhang
DOI:10.1002/anie.201902576
日期:2019.5.27
An efficient nickel‐catalyzedasymmetric hydrogenation of N‐tBu‐sulfonyl imines was developed with excellent yields and enantioselectivities using (R,R)‐QuinoxP* as a chiral ligand. The use of a much lower catalyst loading (0.0095 mol %, S/C=10500) represents the highest catalytic activity for the Ni‐catalyzedasymmetric hydrogenations reported so far. Mechanistic studies suggest that a coordination
一种有效的镍催化的不对称氢化ñ -吨卜-磺酰亚胺是使用具有优良的产率和对映选择性显影([R ,- [R)-作为手性配体的QuinoxP *。使用低得多的催化剂负载量(0.0095 mol%,S / C = 10500)代表了迄今为止报道的Ni催化不对称氢化的最高催化活性。机理研究表明,镍盐及其配合物之间存在配位平衡,过量的镍盐会促进活性镍配合物的形成,因此提高了氢化效率。还通过计算研究了催化循环,以确定对映选择性的来源。发现在过渡态的催化剂和底物之间存在大量的弱吸引作用的广泛网络,这也可能有助于高催化活性。
Iridium-Catalyzed Annulation of Aromatic Imines with 1,3-Dienes<i>via</i>Direct Functionalization of an Aromatic CH Bond
作者:Yusuke Ebe、Miyuki Hatano、Takahiro Nishimura
DOI:10.1002/adsc.201401171
日期:2015.5.4
to give 1‐aminoindane derivatives in high yields with high regio‐ and stereoselectivities. The iridium complex coordinated with a substrate 1,3‐diene displayed high catalyticactivity. The reaction proceeds via the direct formation of the aryliridium(I) species from the aromatic aldimine and an iridium(I) acetate species via a concerted metalation‐deprotonation pathway.