α-L-diarylprolinol as the organocatalyst and K2CO3 as the additive has been accomplished. The spirocyclopropanes were isolated in high yield and up to 85 % ee. Notably, the asymmetric one-pot sequential approach to spirocyclopropanes proved to be a feasible process.
Microtubing-Reactor-Assisted Aliphatic C−H Functionalization with HCl as a Hydrogen-Atom-Transfer Catalyst Precursor in Conjunction with an Organic Photoredox Catalyst
作者:Hong-Ping Deng、Quan Zhou、Jie Wu
DOI:10.1002/anie.201804844
日期:2018.9.24
Chlorine radical, which is classically generated by the homolysis of Cl2 under UV irradiation, can abstract a hydrogenatomfrom an unactivated C(sp3)−H bond. We herein demonstrate the use of HCl as an effective hydrogen‐atom‐transfer catalyst precursor activated by an organic acridinium photoredox catalyst under visible‐light irradiation for C−H alkylation and allylation. The key to success relied
作者:Qian Wan、Shiwu Li、Qiang Kang、Yaofeng Yuan、Yu Du
DOI:10.1021/acs.joc.9b02243
日期:2019.12.6
An enantioselective three-component cascade reduction-Michael additionreaction catalyzed by chiral-at-metal Rh(III) complexes has been developed. With a Hantzsch ester as the hydride source, a number of malononitrile derivatives were prepared in good yields and excellent enantioselectivities. A model that accounts for the origin and influence factors of the stereoselectivity has been proposed based
The Knoevenagel condensation using quinine as an organocatalyst under solvent-free conditions
作者:Kavita Jain、Saikat Chaudhuri、Kuntal Pal、Kalpataru Das
DOI:10.1039/c8nj04219e
日期:——
organocatalyst to afford various electrophilic alkenes in excellent yields (up to 90%). In the presence of a catalytic amount of quinine (15 mol%), the reaction proceeded at room temperature (RT) undersolvent-freeconditions. In this green approach, the organocatalyst was recovered and recycled for up to four cycles without appreciable loss of activity.
Fe-Catalyzed Multicomponent Reactions: The Regioselective Alkoxy Allylation of Activated Olefins and its Application in Sequential Fe Catalysis
作者:André P. Dieskau、Michael S. Holzwarth、Bernd Plietker
DOI:10.1002/chem.201103009
日期:2012.2.20
broadly applicable Fe‐catalyzed regioselectivealkoxyallylation of activated double bonds. Substituted allylic carbonates are converted into the corresponding σ‐enyl Fe complexes by reaction with Bu4N[Fe(CO)3(NO)] (TBAFe) at 30 °C. The liberated alkoxide adds to an activated double bond with the generation of a C‐nucleophile, which is trapped by the σ‐enyl Fe complex in a regioselective manner. Alternatively
我们在此介绍了一种多功能且广泛适用的活化双键的铁催化的区域选择性烷氧基烯丙基化反应。取代的烯丙基碳酸酯通过与Bu 4 N [Fe(CO)3(NO)](TBAFe)在30°C下反应转化为相应的σ-烯基Fe络合物。释放的醇盐会生成C-亲核试剂,从而形成一个活化的双键,该C-亲核试剂会以区域选择性的方式被σ-烯基Fe络合物捕获。或者,该醇盐在使经历迈克尔加成的外部前亲核试剂去质子化中用作碱。该方法的特点是宽泛的官能团耐受性,温和的反应条件,较低的催化剂载量和较高的区域选择性,有利于ipso取代产物。