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Simple Starting Materials (simple + starting_material)
Selected AbstractsOne-Pot Synthesis of Quinoline Derivatives Directly from Terminal Alkynes via Sequential Ruthenium(II) and Acid CatalysisADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010Min Zhang Abstract A convenient one-pot synthesis of 2,3-disubstituted, 2,3,6-trisubstituted, and 2,3,6,7-tetrasubstituted quinoline analogues from terminal alkynes via sequential ruthenium(II) and para -toluenesulfonic acid (p -TSA) co-catalyzed reactions is described. The catalytic process is shown to take place first via intermediate formation of an allyl ketone and then addition of an aniline derivative to the allyl ketone. The p -TSA is a catalyst for both allyl ketone and quinoline synthetic steps. The method allowed us to synthesize a wide range of quinoline derivatives and introduce different substituents by employing various simple starting materials. The reaction allows the synthesis of halogen-containing products. [source] Gold(I)-Catalyzed Cascade for Synthesis of Pyrrolo[1,2- a:2,,1,- c]-/Pyrido[2,1- c]pyrrolo[1,2- a]quinoxalinonesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2010Yu Zhou Abstract An efficient and convenient method was developed for the one-pot construction of the complex polycyclic heterocycles pyrrolo[1,2- a:2,,1,- c]-/pyrido[2,1- c]pyrrolo[1,2- a]quinoxalinones from two simple starting materials via a gold(I)-catalyzed domino reaction. This strategy presents an atom economical and environmentally friendly transformation, in which two new CN bonds and one new CC bond are formed in a one-pot reaction process. [source] Gold(I)-Catalyzed One-Pot Tandem Coupling/Cyclization: An Efficient Synthesis of Pyrrolo-/Pyrido[2,1- b]benzo[d][1,3]oxazin- 1-onesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010Yu Zhou Abstract A highly efficient method has been developed for the one-pot synthesis of multi-ring heterocyclic compounds such as pyrrolo-/pyrido[2,1- b]benzo[d][1,3]oxazin-1-ones from o -aminobenzyl alcohols via a gold(I)-catalyzed tandem coupling/cyclization reaction. Significantly, the strategy presents a straightforward and efficient approach to construct novel tricyclic or polycyclic molecular architectures in which two new CN bonds and one CO bond are formed in a one-pot reaction operation from two simple starting materials. Moreover, a broad spectrum of substrates can participate in the process effectively to produce the desired products in good yields. [source] Pyrazole Synthesis Using a Titanium-Catalyzed Multicomponent Coupling Reaction and Synthesis of WithasomnineADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009Supriyo Majumder Abstract The titanium-catalyzed 3-component coupling of an alkyne, isonitrile, and amine can be used to generate tautomers of 1,3-diimines. These diimines produced in situ undergo cyclization with hydrazine and hydrazine derivatives in a one-pot procedure to provide pyrazoles. Seventeen examples of pyrazoles are provided using this one-pot, 4-component procedure from simple starting materials. The regioselectivity of the alkyne addition can be controlled in some cases with catalyst architecture, and regioselectivity of monosubsituted hydrazines to unsymmetrical 1,3-diimines is discussed. This multicomponent coupling strategy was applied to the synthesis of withasomnine in an efficient procedure, which gave the natural product in 24% overall yield from 4-pentyn-1-ol. [source] Tandem Metal and Organocatalysis in Sequential Hydroformylation and Enantioselective Mannich ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2009Serghei Chercheja Abstract Metal-catalysed hydroformylation is successfully combined with an organocatalysed stereoselective Mannich reaction in a tandem reaction sequence. This novel type of "tandem catalysis" allows access to complex molecular systems with high levels of enantioselectivity, using simple starting materials and an amino acid as the chiral catalyst. [source] Tandem Metal- and Organocatalysis in Sequential Hydroformylation and Enantioselective Aldol ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2007Serghei Chercheja Abstract Metal-catalysed hydroformylation is successfully combined with organocatalysed stereoselective aldol addition into a tandem reaction sequence. This novel type of "tandem catalysis" allows access to complex molecular systems with high levels of enantioselectivity, using simple starting materials and an amino acid as the chiral catalyst. [source] The Influence of Phosphane Ligands on the Versatility of Ruthenium,Indenylidene Complexes in MetathesisCHEMISTRY - A EUROPEAN JOURNAL, Issue 30 2010Julie Broggi Dr. Abstract The aim of the present study is to develop readily available and stable pre-catalysts that could be easily prepared on large scale from simple starting materials. Based on the hypothesis that substitution of classical PCy3 with phosphanes of varying electron-donating properties could be a straightforward manner to improve catalytic activity, a methodical study dealing with the effect of phosphane fine-tuning in ruthenium,indenylidene catalysts was performed. Challenged to establish how the electronic properties of para -substituted phosphane ligands translate into catalyst activity, the versatile behaviour of these new ruthenium,indenylidene complexes was investigated for a number of metathesis reactions. [source] Highly Efficient Access to Bi- and Tricyclic Ketals through Gold-Catalyzed Tandem Reactions of 4-Acyl-1,6-diynesCHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2009Jia Meng Dr. Abstract Single step: Fused bicyclic and bridged tricyclic ketals were synthesized in a single step from the reactions of easily available 4-acyl-1,6-diynes with H2O and alkanols (see scheme). The highly efficient AuCl3 -catalyzed multicomponent domino reactions, involving five CO bond formations, can proceed in a highly regio- and diastereoselective manner at room temperature under air and lead to structures of high molecular complexity from simple starting materials in an atom economic way. [source] A One-Pot Synthesis of Constitutionally Unsymmetrical Rotaxanes Using Sequential CuI -Catalyzed Azide,Alkyne CycloadditionsCHEMISTRY - A EUROPEAN JOURNAL, Issue 14 2008Jason Abstract A one-pot sequential CuI -catalyzed azide,alkyne cycloaddition (CuAAC) strategy is presented for the synthesis of constitutionally unsymmetrical cyclobis(paraquat- p -phenylene)-based rotaxanes in good yields from simple starting materials. The methodology consists of performing multiple CuAAC reactions to stopper a pseudorotaxane in a stepwise manner, the order of which is controlled through silyl-protection and AgI -catalyzed deprotection of a terminal alkyne. The methodology is highlighted by the synthesis of an amphiphilic branched [4]rotaxane. The methodology increases the ability to access ever more complicated mechanically interlocked compounds to serve in devices as sophisticated and functional molecular machinery. [source] | ||||||||||