Cobalt‐Catalyzed Regio‐ and Stereoselective Hydroboration of Allenes
作者:Can Li、Zheng Yang、Lei Wang、Yinlong Guo、Zheng Huang、Shengming Ma
DOI:10.1002/anie.201915716
日期:2020.4.6
pincer-ligand-based cobalt-complex-catalyzed allenehydroboration affording Z-allylic boronates is described. The reaction demonstrates an excellent regio- as well as Z-stereoselectivity and a wide substrate scope that tolerates many functional groups. Based on solvent-assisted electrospray ionization mass spectrometry (SAESI-MS) studies, a rationale for the cobalt-catalyzed hydroboration involving the highly selective
A Ni‐catalyzed [2+2+2] cycloaddition reaction between allene‐ynes and various mono‐, di‐ and tri‐substituted allenes is described. This protocol effectively differentiates allenyl π components and shows broad substrate generality to give highly functionalized carbocycles. A DFT study played a key role in revealing a detailed reaction mechanism that controls site‐, regio‐ and stereoselectivity, which
Epoxidation of 4-Alkylidenecyclopentenones: A Route to the 1-Oxaspiro[2.4]hept-6-en-5-one Framework
作者:Mohammed Ahmar、Stéphane Thomé、Bernard Cazes
DOI:10.1002/ejoc.201201030
日期:2012.12
Thanks to their lack of polarity, the exocyclic double bonds of 4-alkylidenecyclopentenones 4 are selectively epoxidized by MCPBA to give spiroepoxycyclopentenones 7, which feature the nonclassical 1-oxaspiro[2.4]hept-6-en-5-oneframework. Under acidic conditions, compounds 7 undergo ring-opening to afford 4-hydroxy-4-(1-hydroxyalkyl)cyclopentenones 10.
Silicon-Induced Phenanthrene Formation from Benzynes and Allenylsilanes
作者:Jih Ru Hwu、Sharada P. Swain
DOI:10.1002/chem.201203738
日期:2013.5.17
Now directly feasible: The silicon atom in allenylsilanes enabled their reaction with two equivalents of benzynes to generate (α‐phenanthrenyl)vinylsilanes in good to excellent yields through an unprecedented [2+2+2] pathway (see scheme).
Ruthenium(II)‐Catalyzed CH Functionalizations with Allenes: Versatile Allenylations and Allylations
作者:Sachiyo Nakanowatari、Lutz Ackermann
DOI:10.1002/chem.201502785
日期:2015.11.2
Ruthenium(II)‐catalyzed direct CHfunctionalization of aromatic compounds with allenes was achieved under exceedingly mild reaction conditions to yield trisubstituted allenes. The reactions of N‐methoxybenzamides proceeded smoothly in an isohypsic fashion at ambient temperature with high chemo‐ and regioselectivity, thereby providing a versatile means of accessing trisubstituted allenes. Detailed