Alkyne Ligation Handles: Propargylation of Hydroxyl, Sulfhydryl, Amino, and Carboxyl Groups via the Nicholas Reaction
作者:Sarah M. Wells、John C. Widen、Daniel A. Harki、Kay M. Brummond
DOI:10.1021/acs.orglett.6b02088
日期:2016.9.16
The Nicholas reaction has been applied to the installation of alkyne ligation handles. Acid-promoted propargylation of hydroxyl, sulfhydryl, amino, and carboxyl groups using dicobalt hexacarbonyl-stabilized propargylium ions is reported. This method is useful for introduction of propargyl groups into base-sensitive molecules, thereby expanding the toolbox of methods for the incorporation of alkynes
Medium sized trans-cycloalkenes are unusually reactive in the intermolecular Pauson-Khand reaction (PKR) with regard to typical monocyclic alkenes. This is due to the ring strain imparted by the E stereochemistry. The PKR of these alkenes offers a modular, regioselective and straightforward entry to trans fused [n.3.0] bicyclic scaffolds (n = 6-8).
[EN] COBALT COMPOUNDS, METHOD OF MAKING AND METHOD OF USE THEREOF<br/>[FR] COMPOSÉS DE COBALT, PROCÉDÉ DE FABRICATION ET PROCÉDÉ D'UTILISATION ASSOCIÉ
申请人:VERSUM MAT US LLC
公开号:WO2018085257A1
公开(公告)日:2018-05-11
Described herein are cobalt compounds, processes for making cobalt compounds, and compositions comprising cobalt metal-film precursors used for depositing cobalt-containing films (e.g., cobalt, cobalt oxide, cobalt nitride, etc.). Examples of cobalt precursor compounds are (alkyne) dicobalt hexacarbonyl compounds, cobalt enamine compounds, cobalt monoazadienes, and (functionalized alkyl) cobalt tetracarbonyl. Examples of surfaces for deposition of metal-containing films include, but are not limited to, metals, metal oxides, metal nitrides, and metal silicides. Functionalized ligands with groups such as amino, nitrile, imino, hydroxyl, aldehyde, esters, halogens, and carboxylic acids are used for selective deposition on certain surfaces and/or superior film properties such as uniformity, continuity, and low resistance.
Reactions of Co2(CO)8 with RC2R′ alkynes part II. Synthesis of Co2(CO)6(RC2R′) complexes; oligomerization or cyclotrimerization reactions of substituted acetylenes
asymmetrically substituted alkynes lead to complexes Co2(CO)6(RC2R′) (1). These catalyze the cyclotrimerization of alkynes to substituted benzenes. Here we report on the synthesis and characterization of some new complexes 1 and on their reactivity with an excess of alkynes in relatively mild conditions; the characterization of new intermediate Co2(CO)4(RC2R′)3 flyover derivatives (complexes 2) and the
optically pure N-phosphino-p-tolylsulfinamide (PNSO) ligands. Their stability and coordination behavior toward dicobalt-alkyne complexes was evaluated. Selectivities of up to 3:1 were achieved in the ligand exchange process with (mu-TMSC2H)Co2(CO)6. The resulting optically pure major complexes were tested in the asymmetric intermolecular Pauson-Khandreaction and yielded up to 94% ee. X-ray studies of the