An Admix Approach To Determine Counter Anion Effects on Metal-Free Arylation Reactions with Diaryliodonium Salts

A method to determine the effect of counter anions in metal-free arylation reactions of diaryliodonium salts is described. This approach avoids the independent synthesis of individual diaryliodonium salts and potentially enables assessment of a large number of different counter anions, including those that are synthetically challenging to install. Diaryliodonium tosylate salts serve as a general precursor for this approach, and an azide arylation reaction was used to develop this strategy. Further optimization and representative scope of azide arylation is demonstrated in yields that range from 74-95% (89% average). The use of this method as a screening tool has also been validated with arylation reactions of three different nucleophiles employing diphenyliodonium tosylate.

[11C]Cyanation of arylboronic acids in aqueous solutions

A copper-mediated 11C-cyanation method employing arylboronic acids and [11C]HCN has been developed. This method was applied to the radiochemical synthesis of a wide range of aromatic 11C-nitriles in aqueous solutions. The use of readily accessible arylboronic acids as precursors makes this method complementary to the well-established 11C-cyanation methods that utilize aryl halide precursors.

Late stage iodination of biologically active agents using a one-pot process from aryl amines

A tandem process has been developed for the general preparation of aryl iodide compounds from anilines that is also applicable for the late-stage iodination of biologically active agents.

Copper(I)-Phosphinite Complexes in Click Cycloadditions: Three-Component Reactions and Preparation of 5-Iodotriazoles

The remarkable activity displayed by copper(I)–phosphinite complexes of general formula [CuBr(L)] in two challenging cycloadditions is reported: a) the one‐pot azidonation/cycloaddition of boronic acids, NaN₃, and terminal alkynes; b) the cycloaddition of azides and iodoalkynes. These air‐stable catalysts led to very good results in both cases and the expected triazoles could be isolated in pure form under ‘Click‐suitable’ conditions.

Exploiting amphiphilicity: facile metal free access to thianthrenes and related sulphur heterocycles

Benzodithioloimines are reacted with arynes or alkynes substituted with electron-withdrawing groups to afford the corresponding thianthrene or benzo[b][1,4]dithiine derivatives. The transformation takes place under mild reaction conditions without any transition metal. Furthermore, the reaction mode could be expanded to 2-thiocyanatopyrroles yielding pyrrolothiazoles.

Silver(I)-Catalyzed Iodination of Arenes: Tuning the Lewis Acidity of N-Iodosuccinimide Activation

A mild and rapid method for the iodination of arenes that utilizes silver(I) triflimide as a catalyst for activation of N-iodosuccinimide has been developed. The transformation was found to be general for a wide range of anisole, aniline, acetanilide, and phenol derivatives and allowed the late-stage iodination of biologically active compounds such as PIMBA, a SPECT imaging agent of breast cancer, and (-)-IBZM, a dopamine D2 receptor antagonist. The method was also modified for the radioiodination of arenes using a one-pot procedure involving the in situ generation of [(125)I]-N-iodosuccinimide followed by the silver(I)-catalyzed iodination.

Eco-friendly hydrogenation of aromatic aldehyde compounds by tandem dehydrogenation of dimethylamine-borane in the presence of a reduced graphene oxide furnished platinum nanocatalyst

An easy and effective synthetic method has been developed for the reduction of aldehyde compounds in the presence of monodisperse Pt(0)/TPA@rGO NPs as the catalyst.

Direct synthesis of sulfonated dihydroisoquinolinones from N-allylbenzamide and arylsulfinic acids via TBHP-promoted cascade radical addition and cyclization

A novel tert-butyl hydroperoxide (TBHP)-promoted cascade radical addition and cyclization of N-allylbenzamides and arylsulfinic acids to sulfonated dihydroisoquinolinones was developed.

Copper(i) 5-phenylpyrimidine-2-thiolate complexes showing unique optical properties and high visible light-directed catalytic performance

Copper(i) 5-phenylpyrimidine-2-thiolate complexes exhibit intriguing luminescence properties and excellent visible light-directed catalytic activity towards aerobic oxidative hydroxylation of arylboronic acids.

Highly Regioselective Iodination of Arenes via Iron(III)-Catalyzed Activation of N-Iodosuccinimide

An iron(III)-catalyzed method for the rapid and highly regioselective iodination of arenes has been developed. Use of the powerful Lewis acid, iron(III) triflimide, generated in situ from iron(III) chloride and a readily available triflimide-based ionic liquid allowed activation of N-iodosuccinimide (NIS) and efficient iodination under mild conditions of a wide range of substrates including biologically active compounds and molecular imaging agents.

Gold-Catalyzed Proto- and Deuterodeboronation

A mild gold-catalyzed protodeboronation reaction, which does not require acid or base additives and can be carried out in "green" solvents, is described. As a result, the reaction is very functional-group-tolerant, even to acid- and base-sensitive functional groups, and should allow for the boronic acid group to be used as an effective traceless directing or blocking group. The reaction has also been extended to deuterodeboronations for regiospecific ipso-deuterations of aryls and heteroaryls from the corresponding organoboronic acid. Based on density functional theory calculations, a mechanism is proposed that involves nucleophilic attack of water at boron followed by rate-limiting B-C bond cleavage and facile protonolysis of a Au-σ-phenyl intermediate.

Metal-free regioselective C-3 nitration of quinoline N-oxides with tert-butyl nitrite

A direct, regioselective and eco-friendly C3-nitration of quinoline N-oxides using tert-butyl nitrite as both the nitro source and oxidant has been developed. This reaction undergoes a free radical process and can be smoothly scaled up to gram scale.

Photocatalytic hydroxylation of arylboronic acids using continuous flow reactors

Photocatalytic oxidation of mono- and di-substituted arylboronic acids to phenols has been investigated in a continuous flow LED photoreactor. In EtOH–H₂O, conversion was accelerated at 2 MPa; whereas reactions at 0.1 MPa led to 64% desymmetrisation.

Visible-light initiated oxidative cyclization of phenyl propiolates with sulfinic acids to coumarin derivatives under metal-free conditions

A visible-light initiated oxidative cyclization of phenyl propiolates with sulfinic acids has been developed at room temperature under metal-free conditions.