Ligand‐Controlled Regiodivergent Hydroalkylation of Pyrrolines
作者:Deyun Qian、Xile Hu
DOI:10.1002/anie.201912629
日期:2019.12.16
Nickel hydride (NiH) catalyzed hydrocarbonation has emerged as an efficient approach to construct new C-C bonds containing at least one C(sp3 ) center. However, the regioselectivity of this reaction is by far dictated by substrates. Described here is a strategy to achieve two different regioselectivites of hydroalkylation of the same substrates by using ligand control. This strategy enables the first
Photoinduced Palladium‐Catalyzed Dicarbofunctionalization of Terminal Alkynes
作者:Zhen Yang、Rene M. Koenigs
DOI:10.1002/chem.202005391
日期:2021.2.19
photochemical activation of palladium complexes enabled this strategic dicarbofunctionalization via addition of alkyl radicals from secondary and tertiary alkyl iodides and formation of an intermediate palladium vinyl complex that could undergo subsequent Sonogashira reaction with a second alkyne molecule. This alkylation–alkynylation sequence allowed the one‐step synthesis of 1,3‐enynes including heteroarenes
Metal-free visible-light-initiated direct C3 alkylation of quinoxalin-2(1<i>H</i>)-ones and coumarins with unactivated alkyl iodides
作者:Jun Sun、Hua Yang、Bo Zhang
DOI:10.1039/d1gc03992j
日期:——
visible-light-promoted direct C3 alkylation of quinoxalin-2(1H)-ones and coumarinsusing readily accessible unactivated alkyl iodides as alkylation reagents. By applying this new approach, a broad range of valuable 3-alkylated quinoxalin-2(1H)-ones and coumarins (55 examples) can be facilely obtained at room temperature, thus showing the wide utility of this protocol. Notably, this practical reaction occurs under
我们首次报告了使用容易获得的未活化烷基碘作为烷基化试剂对喹喔啉-2(1 H )-酮和香豆素进行可见光促进的直接 C3 烷基化。通过应用这种新方法,可以在室温下轻松获得各种有价值的 3-烷基化 quinoxalin-2(1 H )-ones 和香豆素 (55 个例子),从而显示了该协议的广泛实用性。值得注意的是,这种实际反应发生在无金属和无外部光催化剂的条件下,表现出广泛的底物范围和高官能团耐受性。
Synthesis of Multisubstituted Allenes via Nickel-Catalyzed Cross-Electrophile Coupling
作者:Youxiang Jin、Hao Wen、Feiyan Yang、Decai Ding、Chuan Wang
DOI:10.1021/acscatal.1c04143
日期:2021.11.5
context, we report the successful application of a cross-electrophile strategy in the synthesis of multisubstituted allenes. Under the catalysis of nickel, reductive cross-couplingbetween propargyl carbonates and organoiodides provides an entry to prepare tri- or tetrasubstituted allenes without employing any pregenerated organometallics. Furthermore, propargyl carbonates also prove to be suitable allenylating
Stereoselective Synthesis of Trisubstituted Alkenes through Sequential Iron-Catalyzed Reductive<i>anti</i>-Carbozincation of Terminal Alkynes and Base-Metal-Catalyzed Negishi Cross-Coupling
作者:Chi Wai Cheung、Xile Hu
DOI:10.1002/chem.201504049
日期:2015.12.7
stereoselective synthesis of trisubstituted alkenes is challenging. Here, we show that an iron‐catalyzed anti‐selective carbozincation of terminal alkynes can be combined with a base‐metal‐catalyzed cross‐coupling to prepare trisubstituted alkenes in a one‐pot reaction and with high regio‐ and stereocontrol. Cu‐, Ni‐, and Co‐based catalytic systems are developed for the coupling of sp‐, sp2‐, and sp3‐hybridized