Iron-catalyzed decarboxylative radical addition to chiral azomethine imines upon visible light.

Herein, we disclose an eco-efficient redox-neutral iron-catalyzed decarboxylative radical addition to chiral azomethine imines upon visible light (427 nm) giving cyclic hydrazine derivatives with dr ranging from 82 : 18 to >96 : 4. This earth-abundant metal promoted sequence proceeds efficiently under ligand-free conditions based on a LMCT process and opens a route to new chiral heterocycles.

Vinylogous and stereoselective domino synthesis of pyrano[2,3-c]pyrroles from alkylidene meldrum's acids.

A domino Vinylogous aza-Michael-Aldol-Cyclocondensation (aza-VMAC) reaction was achieved with a series of alkylidene Meldrum's acid derivatives under simple operational conditions paving the way to novel pyrano[2,3-c]pyrroles in an excellent diasteroselectivity (>96 : 4), encompassing the relative control of three contiguous stereocenters.

An Organocatalytic and Stereoselective Vinylogous Domino Process towards Thiochromans.

A highly diastereoselective organocatalyzed domino vinylogous sulfa-Michael-aldol-cyclocondensation (VMAC) reaction has been developed using alkylidene Meldrum's acid as dienes highlighting two vinylogous steps, an unprecedented sulfa-1,6-conjugate addition and a diastereoselective aldol reaction triggering a formal (4+2) cycloaddition. This work opens a new route towards bio-relevant and original tricyclic thiochroman derivatives.

Recent Advances in Catalytic and Technology-Driven Radical Addition to N,N-Disubstituted Iminium Species.

Recently, radical chemistry has grown exponentially in the toolbox of organic synthetic chemists. Upon the (re)introduction of modern catalytic and technology-driven strategies, the implementation of highly reactive radical species is currently facilitated while expanding the scope of numerous synthetic methodologies. In this context, this review intends to cover the recent advances in radical-based transformations of N,N-disubstituted iminium substrates that encompass unique reactivities with respect to imines or protonated iminium salts. In particular, we have focused on the literature concerning the dipole type substrates, such as nitrones or azomethine imines, together with the chemistry of N+-X- (X = O, NR) azaarenium dipoles, which proved to be very versatile platforms in that field of research. The N-alkylazaarenium salts were been considered, which demonstrated specific reactivity profiles in radical chemistry.

Chelation-assisted C-C bond activation of biphenylene by gold(i) halides.

A chelation-assisted oxidative addition of gold(i) into the C-C bond of biphenylene is reported here. The presence of a coordinating group (pyridine, phosphine) in the biphenylene unit enabled the use of readily available gold(i) halide precursors providing a new, straightforward entry towards cyclometalated (N^C^C)- and (P^C)-gold(iii) complexes. Our study, combining spectroscopic and crystallographic data with DFT calculations, showcases the importance of neighboring, weakly coordinating groups towards the successful activation of strained C-C bonds by gold.

Phosphorescent κ3 -(N

Efficient OLED devices have been fabricated using organometallic complexes of platinum group metals. Still, the high material cost and low stability represent central challenges for their application in commercial display technologies. Based on its innate stability, gold(III) complexes are emerging as promising candidates for high-performance OLEDs. Here, a series of alkynyl-, N-heterocyclic carbene (NHC)- and aryl-gold(III) complexes stabilized by a κ3 -(N^C^C) template have been prepared and their photophysical properties have been characterized in detail. These compounds exhibit good photoluminescence quantum efficiency (ηPL ) of up to 33 %. The PL emission can be tuned from sky-blue to yellowish green colors by variations on both the ancillary ligands as well as on the pincer template. Further, solution-processable OLED devices based on some of these complexes display remarkable emissive properties (ηCE 46.6 cd.A-1 and ηext 14.0 %), thus showcasing the potential of these motifs for the low-cost fabrication of display and illumination technologies.

κ3 -(N

Gold(III) carboxylate species, stabilized by a κ3 -(N^C^C) ligand template, are presented herein. A η1 -AuIII -C(O)-OH species has been characterized under cryogenic conditions as a result of the nucleophilic attack of an ammonium hydroxide onto a dinuclear µ-CO2 -κ3 -(N^C^C)AuIII precursor. Thermal decomposition for these species proceeds by an unusual decarbonylation process, in contrast to typical decarboxylation pathways observed in related metallocarboxylic acids.

Minisci-Photoredox-Mediated α-Heteroarylation of N-Protected Secondary Amines: Remarkable Selectivity of Azetidines.

The development of a general, mild, and functional-group-tolerant direct functionalization of N-heteroarenes by C-H functionalization with N-protected amines, including azetidines under Minisci-mediated photoredox conditions, is reported. A broad scope of substituted azetidines, including spirocyclic derivatives, and heterocycles were explored. This reaction enables the production of sp3-rich complex druglike structures in one step from unactivated feedstock amines and heterocycles.

Rhodium-catalyzed cyclopropanation of fluorinated olefins: a straightforward route to highly functionalized fluorocyclopropanes.

An efficient access to highly functionalized monofluorocyclopropanes is described. The developed methodology allowed straightforward access to a large panel of polysubstituted fluorinated cyclopropanes in good to excellent yields and good diastereoselectivities. The Rh-catalyzed cyclopropanation proved to be efficient on several fluorinated olefins and several diazo compounds. This method represents the first general route to complex fluorinated cyclopropanes.