Showing papers in "Organic Letters in 2016"

TL;DR: A well-defined nonprecious metal cobalt(II) catalyst based on a pincer PNP ligand has been employed for the efficient N-alkylation of both aromatic and aliphatic amines with alcohols with high chemoselectivity.

TL;DR: This report constitutes the first catalytic activation of the amide N-C(O) bond by rhodium, and it is expected that this concept will have broad implications for using amides as coupling partners for C-H activation beyond the work described herein.

TL;DR: A facile, straightforward protocol was established for diarylannulated sulfide and selenide construction through S-I and Se-I exchange without transition metal assistance.

TL;DR: This research exhibited the potential of transition-metal-catalyzed activation of methanol as a C1 source for the construction of heterocycles.

TL;DR: C-H activation of arenes has been established as an important strategy for heterocycle synthesis via annulations between arenes and unsaturated coupling partners, but nitriles failed to act as such a coupling partner.

TL;DR: The serendipitous discovery of this reaction and its utilization for the thioetherification of various aryl and heteroaryl bromides with a diverse array of thiols is described, enabling a wide range of functional groups, including those bearing protic moieties, to be tolerated.

TL;DR: This mechanistically novel strategy allows the construction of 2-fluoroalkylated 3-iodoquinoxalines in high yields under visible-light irradiation at room temperature.

TL;DR: The synthesis of β-hydroxysulfones from sulfonyl chlorides and styrenes in the presence of water by a visible light mediated atom transfer radical addition (ATRA)-like process utilizing fac[Ir(ppy)3] as photoredox catalyst was developed in high yields, demonstrating the possibility of sequential Photoredox processes.

TL;DR: The well-defined aluminum monohydride compound [{(2,4,6-Me3-C6H2)NC(Me)}2(Me)(H)]AlH·(NMe2Et) (1) catalyzes hydroboration of a wide range of aldehydes and ketones under mild reaction conditions.

TL;DR: This reaction is an environmentally benign process implementing inexpensive, earth-abundant nonprecious metal catalysts and is based on the acceptorless alcohol dehydrogenation concept.

TL;DR: A cobalt(III)-catalyzed C-H/N-H bond functionalization for the synthesis of 1-aminoisoquinolines from aryl amidines and diazo compounds has been developed and features a broad substrate scope.

TL;DR: An unprecedented example of Pd-catalyzed difluoromethylation of aryl boronic acids with bromodifluoroacetate is described, providing a useful protocol for drug discovery and development.

TL;DR: The Co(III)-catalyzed redox-neutral coupling between arenes and alkynes using an NH amide as an electrophilic directing group is reported, enabling C-H activation/coupling afforded quinolines with water as the sole byproduct.

TL;DR: This investigation revealed that the cobalt catalyst is uniquely suited to this transformation due to its strong Lewis acidity and high sensitivity to steric hindrance.

TL;DR: This research exhibits the potential for the construction of heterocycles via acceptorless dehydrogenative reactions in water catalyzed by water-soluble metal-ligand bifunctional catalysts.

TL;DR: A chiral thiourea catalyzed asymmetric 1,6-conjugate addition of para-quinone methides with dicyanoolefins has been developed and the preliminary mechanistic study showed that the remote stereocontrol was achieved through intermolecular hydrogen-bond interaction for the first time.

TL;DR: Donor-acceptor cyclopropanes are reacted under the influence of a Lewis acid with hydrazonyl chlorides to afford tetrahydropyridazines and the structure of a typical product was confirmed by X-ray crystallography.

TL;DR: Visible light along with 5 mol % eosin B catalyzed the first direct C-H phosphorylation of thiazole derivatives with diarylphosphine oxides by a photoredox process in the absence of an external oxidant.

TL;DR: Under visible-light photoredox conditions, difluoromethyltriphenylphosphonium bromide was used as the precursor of the CF2H radical for bromodiflu oromethylation of alkenes and the presence of catalytic CuBr2 resulted in the selective formation of the bromodelectric products.

TL;DR: An unexpected Cu-catalyzed deoxygenative C2-sulfonylation reaction of quinoline N-oxides in the presence of radical initiator K2S2O8 was developed that used sodium sulfinate as a sulfonyl coupling partner.

TL;DR: The synthesis of polyfunctionalized aminothioalkenes has been realized via the direct C-H sulfenylation of enaminones and analogous enamines through simple KIO3 catalysis under aerobic conditions without employing any transition metal catalyst or additional oxidant.

TL;DR: A cobalt(III)-catalyzed α-fluoroalkenylation of different arenes with readily available gem-difluorostyrenes has been realized under mild and redox-neutral conditions and offers a step-economical access to various 1,2-diaryl-substituted monofluoroalkenes in excellent Z selectivity in moderate to excellent yields.

TL;DR: A novel [3 + 2] annulation between para-quinone methides and vinylcyclopropanes for the synthesis of spiro[4.5]deca-6,9-diene-8-ones has been described and the reaction exhibited good functional group tolerance and scalability.

TL;DR: The pyrene-substituted o-carborane dyads were synthesized via the insertion reaction between decaborane and 1-ethynylpyrene in the presence of Lewis base in a good yield and extremely bright luminescent compounds with solid-state emission properties were obtained.

TL;DR: An efficient double C-N bond formation sequence to prepare highly substituted quinazolines utilizing benzimidates and dioxazolones under the catalytic redox-neutral [Cp*RhCl2]2/AgBF4 system is reported.

TL;DR: A copper-mediated nucleophilic radiofluorination of aryl- and vinylstannanes with [18F]KF is described, which delivers a clinically validated dose of 200 ± 20 mCi with a high specific activity of 2400 ± 900 Ci/mmol.

TL;DR: The reaction incorporates a tandem cyclization/dearomatization process to afford various difluoromethylated 2-azaspiro[4.5]deca-6,9-diene-3,8-diones bearing adjacent quaternary stereocenters under mild conditions in moderate to excellent yields.

TL;DR: Rhodium(III)-catalyzed C-H activation of heteroarenes and functionalization with bifunctional substrates such as anthranils allows facile construction of quinoline-fused heterocycles under redox-neutral conditions.

TL;DR: A mild Co(III)-catalyzed oxidative annulation of N-arylureas and internal alkynes has been developed, providing a new opportunity for the synthesis of diverse indoles.

TL;DR: A novel Fe-catalyzed hydroalkylation of olefins with para-quinone methides (p-QMs) for accessing phenols has been developed and the reaction conditions are mild and the substrate scopes are broad.