7297-72-5Relevant academic research and scientific papers
Difluoro- and trifluoro diazoalkanes-complementary approaches in batch and flow and their application in cycloaddition reactions
Hock, Katharina J.,Mertens, Lucas,Metze, Friederike K.,Schmittmann, Clemens,Koenigs, Rene M.
, p. 905 - 909 (2017/08/14)
Herein we report on applications of fluorinated diazoalkanes in cycloaddition reactions, with the emphasis on studying subtle differences between diverse fluorinated diazo compounds. These differences led to two major synthetic protocols in batch and flow that allow the safe and scalable synthesis of fluoroalkyl-, sulfone-substituted pyrazolines.
Palladium-Catalyzed Synthesis of Aryl Vinyl Sulfides via 1,3-Oxathiolanes As Vinyl Sulfide Surrogates
Schmink, Jason R.,Dockrey, Summer A. Baker,Zhang, Tianyi,Chebet, Naomi,Van Venrooy, Alexis,Sexton, Mary,Lew, Sarah I.,Chou, Steffany,Okazaki, Ami
supporting information, p. 6360 - 6363 (2016/12/23)
A nontraditional approach to synthesizing aryl vinyl sulfides is described. 2,2-Diphenyl-1,3-oxathiolane slowly liberates a vinyl sulfide anion under basic conditions. Using a Pd/Xantphos catalyst system to activate a wide range of aryl bromides, this transient sulfide species can be effectively trapped and fed into a traditional Pd0/PdII catalytic cycle. Scope and limitations of the methodology are presented along with significant discussion of a competitive C-S bond activation by this catalyst system.
An efficient metal-free pathway to vinyl thioesters with calcium carbide as the acetylene source
Rodygin, Konstantin S.,Ananikov, Valentine P.
supporting information, p. 482 - 486 (2016/01/30)
Chemical reactions involving high-pressure acetylene are not easily performed in a standard laboratory setup. The risk of explosion and technical difficulties drastically complicate the equipment and greatly increase the cost. In this study, we propose th
Vinyl sulfoxides as stereochemical controllers in intermolecular Pauson-Khand reactions: Applications to the enantioselective synthesis of natural cyclopentanoids
Rodriguez Rivero, Marta,Alonso, Ines,Carretero, Juan C.
, p. 5443 - 5459 (2007/10/03)
The use of sulfoxides as chiral auxiliaries in asymmetric intermolecular Pauson-Khand reactions is described. After screening a wide variety of substituents on the sulfur atom in α,β-unsaturated sulfoxides, the readily available o-(N,N-dimethylamino)phenyl vinyl sulfoxide (1i) has proved to be highly reactive with substituted terminal alkynes under N-oxide-promoted conditions (CH3CN, 0°C). In addition, these Pauson-Khand reactions occurred with complete regioselectivity and very high diastereoselectivity (de = 86→96%, (S,RS) diastereomer). Experimental studies suggest that the high reactivity exhibited by the vinyl sulfoxide 1i relies on the ability of the amine group to act as a soft ligand on the alkyne dicobalt complex prior to the generation of the cobaltacycle intermediate. On the other hand, both theoretical and experimental studies show that the high stereoselectivity of the process is due to the easy thermodynamic epimerization at the C5 center in the resulting 5-sulfinyl-2- cyclopentenone adducts. When it is taken into account that the known asymmetric intermolecular Pauson-Khand reactions are limited to the use of highly reactive bicyclic alkenes, mainly norbornene and norbornadiene, this novel procedure constitutes the first asymmetric version with unstrained acyclic alkenes. As a demonstration of the synthetic interest of this sulfoxide-based methodology in the enantioselective preparation of stereochemically complex cyclopentanoids, we have developed very short and efficient syntheses of the antibiotic (-)-pentenomycin I and the (-)-aminocyclopentitol moiety of a hopane triterpenoid.
Asymmetric Intermolecular Pauson-Khand Reactions of Unstrained Olefins: The (o-Dimethylamino)phenylsulfinyl Group as an Efficient Chiral Auxiliary
Rodriguez Rivero, Marta,De La Rosa, Juan Carlos,Carretero, Juan Carlos
, p. 14992 - 14993 (2007/10/03)
The first asymmetric version of intermolecular Pauson?Khand reactions of unstrained alkenes is described. Generally simple acyclic alkenes exhibit low reactivity and regioselectivity in intermolecular Pauson?Khand reactions; however, o-(dimethylamino)phen
