Man Kin Tse

Bio: Man Kin Tse is an academic researcher from University of Rostock. The author has contributed to research in topics: Catalysis & Hydrogen peroxide. The author has an hindex of 39, co-authored 98 publications receiving 4696 citations. Previous affiliations of Man Kin Tse include Leibniz Institute for Neurobiology & The Chinese University of Hong Kong.

Remarkably Selective Iridium Catalysts for the Elaboration of Aromatic C-H Bonds

Abstract: Arylboron compounds have intriguing properties and are important building blocks for chemical synthesis. A family of Ir catalysts now enables the direct synthesis of arylboron compounds from aromatic hydrocarbons and boranes under "solventless" conditions. The Ir catalysts are highly selective for C-H activation and do not interfere with subsequent in situ transformations, including Pd-mediated cross-couplings with aryl halides. By virtue of their favorable activities and exceptional selectivities, these Ir catalysts impart the synthetic versatility of arylboron reagents to C-H bonds in aromatic and heteroaromatic hydrocarbons.

Tuning catalytic activity between homogeneous and heterogeneous catalysis: improved activity and selectivity of free nano-Fe2O3 in selective oxidations.

Abstract: 1 before use (a) and afterreuse five times (b).[*]Dr. F. Shi, Dr. M. K. Tse, Prof. Dr. M. BellerLeibniz-Institut fr Katalyse e.V. an der Universitt RostockAlbert-Einstein-Strasse 29a, 18059 Rostock (Germany)andCenter for Life Science Automation (CELISCA)University of RostockFriedrich-Barnewitz-Strasse 818119 Rostock-Warnemnde (Germany)Fax: ( +49)381-1281-5000E-mail: matthias.beller@catalysis.deDr. M.-M. Pohl, Dr. A. BrcknerLeibniz-Institut fr Katalyse e.V.Universitt Rostock, Ausenstelle BerlinRichard-Willsttter-Strasse 3, 12489 Berlin (Germany)Dr. S. ZhangSpecial Functional Material Laboratory, Henan University475001, Kaifeng (China)[**]This work was supported by the State of Mecklenburg-WesternPommerania, the Deutsche Forschungsgemeinschaft (SPP 1118and Leibniz prize), and the Deutsche FMER (BMBF). F.S. thanks theAlexander-von-Humboldt-Stiftung for an AvH Fellowship.Supporting information for this article is available on the WWWunder http://www.angewandte.org or from the author.

Green and efficient synthesis of sulfonamides catalyzed by nano-Ru/Fe(3)O(4).

Abstract: The environmentally benign synthesis of carbon-nitrogen bonds continues to be an active and challenging field of chemical research. Here, a novel, environmentally benign method for the direct coupling of sulfonamides and alcohols is described. Despite the importance of sulfonamide derivatives as intermediates in drug synthesis, till now such transformations are rarely known. For the first time a domino dehydrogenation-condensation-hydrogenation sequence of alcohols and sulfonamides has been realized in the presence of a nanostructured catalyst. The magnetic property of the catalyst system allows for convenient isolation of the product and efficient recycling of the catalyst. A variety of coupling reactions of benzylic alcohols and sulfonamides including various heterocycles were successfully realized, often with >80% isolated yield. Advantageously, only one equivalent of the primary alcohol is consumed in the process. Mechanistic investigations of the competitive reactions of benzyl alcohol and d(7)-benzyl alcohol with p-toluenesulfonamide revealed a kinetic isotope effect (k(H)/k(D)) of 2.86 (+/-0.109) for the dehydrogenation of benzyl alcohol and 0.74 (+/-0.021) for the hydrogenation of N-benzylidene-p-toluenesulfonamide intermediate, which suggests dehydrogenation of the alcohol to be the rate determining step.

Copper‐Catalyzed Alkylation of Sulfonamides with Alcohols

Abstract: the Chinese Academy of Sciences;the DFG (SPP 1118 and Leibniz Prize), and the BMBF. F. Shi thanks the Alexander-von-Humboldt-Stiftung for an AvH Fellowship

Palladium(II)-catalyzed C-H activation/C-C cross-coupling reactions: versatility and practicality.

Abstract: Pick your Pd partners: A number of catalytic systems have been developed for palladium-catalyzed CH activation/CC bond formation. Recent studies concerning the palladium(II)-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle are discussed (see scheme), and the versatility and practicality of this new mode of catalysis are presented. Unaddressed questions and the potential for development in the field are also addressed. In the past decade, palladium-catalyzed CH activation/CC bond-forming reactions have emerged as promising new catalytic transformations; however, development in this field is still at an early stage compared to the state of the art in cross-coupling reactions using aryl and alkyl halides. This Review begins with a brief introduction of four extensively investigated modes of catalysis for forming CC bonds from CH bonds: PdII/Pd0, PdII/PdIV, Pd0/PdII/PdIV, and Pd0/PdII catalysis. A more detailed discussion is then directed towards the recent development of palladium(II)-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle. Despite the progress made to date, improving the versatility and practicality of this new reaction remains a tremendous challenge.

C-H bond functionalization: emerging synthetic tools for natural products and pharmaceuticals

Abstract: The direct functionalization of C-H bonds in organic compounds has recently emerged as a powerful and ideal method for the formation of carbon-carbon and carbon-heteroatom bonds. This Review provides an overview of C-H bond functionalization strategies for the rapid synthesis of biologically active compounds such as natural products and pharmaceutical targets.

C−H Activation for the Construction of C−B Bonds

Abstract: A number of studies were conducted to demonstrate C-H activation for the construction of C-B bonds. Investigations revealed that the conversion of C-H bonds to C-B bonds was both thermodynamically and kinetically favorable. The reaction at a primary C-H bond of methane or a higher alkene B 2(OR)4 formed an alkylboronate ester R' -B(OR)2 and the accompanying borane H-B(OR2. The ester and the borane were formed on the basis of calculated bond energies for methylboronates and dioaborolanes. The rates of key steps along the reaction pathway for the conversion of a C-H bond in an alkane or arene to the C-B bond in an alkyl or arylboronate ester were favorable. These studies also highlighted the accessible barriers for C-H bond cleavage and B-C bond formation during the borylation of alkanes and arenes.

C-H Bond Functionalization in Complex Organic Synthesis

Abstract: Direct and selective replacement of carbon-hydrogen bonds with new bonds (such as C-C, C-O, and C-N) represents an important and long-standing goal in chemistry. These transformations have broad potential in synthesis because C-H bonds are ubiquitous in organic substances. At the same time, achieving selectivity among many different C-H bonds remains a challenge. Here, we focus on the functionalization of C-H bonds in complex organic substrates catalyzed by transition metal catalysts. We outline the key concepts and approaches aimed at achieving selectivity in complex settings and discuss the impact these reactions have on synthetic planning and strategy in organic synthesis.

Palladium- and Copper-Catalyzed Arylation of Carbon-Hydrogen Bonds

Abstract: The transition-metal-catalyzed functionalization of C-H bonds is a powerful method for generating carbon-carbon bonds. Although significant advances to this field have been reported during the past decade, many challenges remain. First, most of the methods are substrate-specific and thus cannot be generalized. Second, conversions of unactivated (i.e., not benzylic or alpha to heteroatom) sp(3) C-H bonds to C-C bonds are rare, with most examples limited to t-butyl groups, a conversion that is inherently simple because there are no beta-hydrogens that can be eliminated. Finally, the palladium, rhodium, and ruthenium catalysts routinely used for the conversion of C-H bonds to C-C bonds are expensive. Catalytically active metals that are cheaper and less exotic (e.g., copper, iron, and manganese) are rarely used. This Account describes our attempts to provide solutions to these three problems. We have developed a general method for directing-group-containing arene arylation by aryl iodides. Using palladium acetate as the catalyst, we arylated anilides, benzamides, benzoic acids, benzylamines, and 2-substituted pyridine derivatives under nearly identical conditions. We have also developed a method for the palladium-catalyzed auxiliary-assisted arylation of unactivated sp(3) C-H bonds. This procedure allows for the beta-arylation of carboxylic acid derivatives and the gamma-arylation of amine derivatives. Furthermore, copper catalysis can be used to mediate the arylation of acidic arene C-H bonds (i.e., those with pK(a) values <35 in DMSO). Using a copper iodide catalyst in combination with a base and a phenanthroline ligand, we successfully arylated electron-rich and electron-deficient heterocycles and electron-poor arenes possessing at least two electron-withdrawing groups. The reaction exhibits unusual regioselectivity: arylation occurs at the most hindered position. This copper-catalyzed method supplements the well-known C-H activation/borylation methodology, in which functionalization usually occurs at the least hindered position. We also describe preliminary investigations to determine the mechanisms of these transformations. We anticipate that other transition metals, including iron, nickel, cobalt, and silver, will also be able to facilitate deprotonation/arylation reaction sequences.