7 research outputs found
Catalytic Nitrene Transfer To Alkynes: A Novel and Versatile Route for the Synthesis of Sulfinamides and Isothiazoles
A novel transformation is reported for the reaction of terminal or internal alkynes with the nitrene precursor PhI=NTs (Ts=p-toluenesulfonyl) in the presence of catalytic amounts of Tp(Br3)Cu(NCMe) (Tp(Br3)=hydrotris(3,4,5-tribromo-pyrazolylborate). Two products containing an imine functionality have been isolated from the reaction mixtures, identified as sulfinamides and isothiazoles. The former correspond to the formal reduction of the sulfone group into sulfoxide, whereas the latter involves the insertion of an alkyne carbon atom into the aromatic ring of the N-tosyl moiety.Support for this work was provided by the MINECO (CTQ2014-52769-C3-R-1, CTQ2014-57761-R, Severo Ochoa Excellence Accreditation 2014-2018 SEV-2013-0319, Red Intecat CTQ2014-52974-REDC) and by a FPU fellowship (M.R.R.). We thank Prof. Antonio Echavarren for helpful comments and discussions
Nucleophilic Trifluoromethylation Reactions Involving Copper(I) Species: From Organometallic Insights to Scope
Over the last decades, trifluoromethyl copper(I) complexes have
played a key role as reactive species in the formation of CâCF3 bond-forming
reactions. This Short Review covers not only select examples of relevant Cumediated
or catalyzed nucleophilic trifluoromethylation reactions, one of the
most active fields in organic synthesis, but also provides a comprehensive
picture of the real behavior of these copper species, including ubiquitous
cuprates, in the reaction media
Sustainable knowledge-driven approaches in transition metalcatalyzed transformations
The sustainable synthesis of relevant scaffolds for their use in the pharmaceutical, agrochemical and material sectors
constitutes one of the most urgent challenges that the chemical community needs to overcome. In this context, the development of
innovative and more efficient catalytic processes based on fundamental understanding of the underlying reaction mechanisms remains
a largely unresolved challenge for academic and industrial chemists. Here, we cover selected examples of computational and
experimental knowledge-driven approaches for the rational design of transition metal catalyzed transformations
New vistas in transmetalation with discrete âAgCF3â species: Implications in Pd-mediated trifluoromethylation reactions
This work describes the employment of discrete âAgCF3â complexes as efficient transmetalating agents to PdIIto surmount overlooked challenges related to the transmetalation step in Pd- catalyzed trifluoromethylation processes. We report the participation of a unique silver ate (Cs)[Ag(CF3)2] complex, under stoichiometric and catalytic conditions, in the unprecedented one-pot formation of PhCF3 using PhI as starting material. Moreover, we show that the transmetalation step, which is often ignored in these transformations, can also determine the success or failure of the coupling process
Catalytic nitrene transfer yo alkynes: a novel and versatile route for the synthesis of sulfinamides and isothiazoles
A novel transformation is reported for the reaction of terminal or internal alkynes with the nitrene precursor PhI=NTs (Ts=pâtoluenesulfonyl) in the presence of catalytic amounts of TpBr3Cu(NCMe) (TpBr3=hydrotris(3,4,5âtribromoâpyrazolylborate). Two products containing an imine functionality have been isolated from the reaction mixtures, identified as sulfinamides and isothiazoles. The former correspond to the formal reduction of the sulfone group into sulfoxide, whereas the latter involves the insertion of an alkyne carbon atom into the aromatic ring of the Nâtosyl moiety.Support for this work was provided by the MINECO (CTQ2014â52769âC3âRâ1, CTQ2014â57761âR, Severo Ochoa Excellence Accreditation 2014â2018 SEVâ2013â0319, Red Intecat CTQ2014â52974âREDC) and by a FPU fellowship (M.R.R.)
Exploring the role of coinage metallates in trifluorometalation: a combined experimental and theoretical study
Despite the known nucleophilic nature of [M(CF3)2]â(M =
Cu, Ag, Au), their participation in trifluoromethylation reactions of aryl
halides remains unexplored. Herein, we report, for the first time, the
selective access to Cu(CF3)2
â species, ubiquitous in Cu-mediated
trifluoromethylations, and we rationalize its complex mechanistic
scenario and its behavior compared to its silver and gold congeners
through a mixture of experimental and computational approaches