Unique catalysis of gold nanoparticles in the chemoselective hydrogenolysis with H2: cooperative effect between small gold nanoparticles and a basic support
Gold nanoparticles on hydrotalcite act as a heterogeneous catalyst for the chemoselective hydrogenolysis of various allylic carbonates to the corresponding terminal alkenes using H2 as a clean reductant. The combination of gold nanoparticles and basic supports elicited significantly unique and selective catalysis in the hydrogenolysis.
Asymmetric Allylic Substitution Catalyzed byC1-Symmetrical Complexes of Molybdenum: Structural Requirements of the Ligand and the Stereochemical Course of the Reaction
作者:Andrei V. Malkov、Laure Gouriou、Guy C. Lloyd-Jones、Ivo Starý、Vratislav Langer、Paul Spoor、Victoria Vinader、Pavel Kočovský
DOI:10.1002/chem.200501574
日期:2006.9.6
Application of newchiral ligands (R)-(-)-12 a and (S)-(+)-12 c (VALDY), derived from amino acids, to the title reaction, involving cinnamyl (linear) and isocinnamyl (branched) type substrates (4 and 5 --> 6), led to excellent regio- and enantioselectivities (>30:1, < or =98 % ee), showing that ligands with a single chiral center are capable of high asymmetric induction. The structural requirements
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。
Self-Assembled Poly(imidazole-palladium): Highly Active, Reusable Catalyst at Parts per Million to Parts per Billion Levels
作者:Yoichi M. A. Yamada、Shaheen M. Sarkar、Yasuhiro Uozumi
DOI:10.1021/ja210772v
日期:2012.2.15
uniformly dispersed in MEPI-Pd. MEPI-Pd was utilized for the allylic arylation/alkenylation/vinylation of allylic esters and carbonates with aryl/alkenylboronic acids, vinylboronicacid esters, and tetraaryl borates. Even 0.8-40 mol ppm Pd of MEPI-Pd efficiently promoted allylic arylation/alkenylation/vinylation in alcohol and/or water with a catalytic turnover number (TON) of 20,000-1,250,000. Furthermore
Rhodium-Catalyzed Asymmetric N−H Functionalization of Quinazolinones with Allenes and Allylic Carbonates: The First Enantioselective Formal Total Synthesis of (−)-Chaetominine
作者:Yirong Zhou、Bernhard Breit
DOI:10.1002/chem.201705059
日期:2017.12.22
An unprecedented asymmetric N−H functionalization of quinazolinones with allenes and allylic carbonates was successfully achieved by rhodium catalysis with the assistance of chiral bidentate diphosphine ligands. The high efficiency and practicality of this method was demonstrated by a low catalyst loading of 1 mol % as well as excellent chemo‐, regio‐, and enantioselectivities with broad functional