Visible-light-mediated selenocyclization of -vinylanilides with diselenides.

Herein, we describe a visible-light-mediated selenocyclization of -vinylanilides with diselenides, which provides a mild and effective method for the synthesis of selenylated 4-3,1-benzoxazines. This reaction proceeds under metal-free conditions, without the need for a chemical oxidant or a controlled O atmosphere and shows a broad substrate scope with yields of up to 98%. Additionally, the process is easily scalable to the gram scale.

Synthesis of 3-sulfonylisoindolin-1-ones from olefinic amides and sodium sulfinates electrooxidative tandem cyclization.

Sulfonyl groups are motifs that are widely found in biologically active compounds and drug molecules, many isolated natural products as well as pharmaceuticals contain sulfonyl groups. Herein, we present the synthesis of sulfonyl-substituted isoindolones by a electrochemical oxidative radical cascade cycloaddition reaction of olefinic amides with sodium sulfite under oxidant- and catalyst-free conditions. Various olefinic amides and sodium sulfinates were compatible and gave the desired products in yields up to 99%.

Correction: Iron-promoted free radical cascade difunctionalization of unsaturated benzamides with silanes.

Correction for 'Iron-promoted free radical cascade difunctionalization of unsaturated benzamides with silanes' by Yaxin Ge , , 2020, , 12656-12659, https://doi.org/10.1039/D0CC05213B.

Free Radical Promoted Trifluoromethylthiolation of Alkynes to Access SCF-Containing Dibenzazepines or Dioxodibenzothiazepines.

Persulfate-promoted radical cascade trifluoromethylthiolation of aryl acetylenes with AgSCF provides a simple reaction system for the synthesis of SCF-substituted dibenzazepines or dioxodibenzothiazepines with good / selectivity. The single-crystal X-ray diffraction data confirms the structures of the final products. A series of scaled-up experiments, further transformations, and radical inhibition experiments were operated in the reaction system.

Iron-promoted free radical cascade difunctionalization of unsaturated benzamides with silanes.

Iron salt/peroxide promoted cascade difunctionalization of unsaturated benzamides with silanes has been reported. It provides a convenient, highly selective, and efficient protocol for the synthesis of various silylated dihydroisoquinolinones and 1,3-isoquinolinediones. In particular, the present methodology only gives cyclization products in good isolated yields under the typical conditions.

Silver or cerium-promoted free radical cascade difunctionalization of o-vinylanilides with sodium aryl- or alkylsulfinates.

An efficient cascade oxysulfonylation of o-vinylanilides with sodium aryl- or alkylsulfinates by a free radical mechanism has been developed, which provides a mild, facile and convenient method for the synthesis of various benzoxazines. Control experiments, including gram-level reactions and mechanistic studies, are involved in the reaction system.

Copper-catalyzed radical cascade oxyalkylation of olefinic amides with simple alkanes: highly efficient access to benzoxazines.

A copper-catalyzed C(sp)-H bond functionalization of simple alkanes with olefinic amides was developed for the efficient synthesis of important benzoxazine derivatives. It involves new C-C and C-O bond formation in one step via a radical cascade process.

Metal-free oxidative functionalization of a C(sp(3))-H bond adjacent to nitrogen and intramolecular aromatic cyclization for the preparation of 6-amidophenanthridines.

A metal-free cyclization reaction of 2-isocyanobiphenyls with amide derivatives by using tert-butyl peroxybenzoate (TBPB) as oxidant was developed, which provided an access to pharmacologically interesting 6-amidophenanthridine compounds. The reactions proceeded through a sequence of functionalization of the C(sp(3))-H bond adjacent to the nitrogen atom and intramolecular radical aromatic cyclization with good chemistry yields.

Metal-free oxidative functionalization of C(sp(3))-H bond adjacent to oxygen and radical addition to olefins.

A DTBP-promoted oxidative functionalization of a C(sp(3))-H bond adjacent to oxygen and intermolecular radical addition to olefins without use of any metal catalyst or photoredox catalysis is reported. The reaction has a wide scope of olefin, alcohol, and cycloether substrates, which provides an easy way for direct preparation of α,ω-amino alcohols.

Metal-Free Preparation of Cycloalkyl Aryl Sulfides via Di-tert-butyl Peroxide-Promoted Oxidative C(sp3)[BOND]H Bond Thiolation of Cycloalkanes.

A concise thiolation of C(sp)-H bond of cycloalkanes with diaryl disulfides in the presence of oxidant of di--butylperoxide (DTBP) has been developed. This reaction without using any of metal catalyst, tolerates varieties of disulfides and cycloalkanes substrates, giving good to excellent chemical yields, which provides a useful approach to cycloalkyl aryl sulfides from unactivated cycloalkanes.

Metal-free oxidative C(sp(3))-H bond functionalization of alkanes and alkylation-initiated radical 1,2-aryl migration in α,α-diaryl allylic alcohols.

An oxidative C(sp(3))-H bond functionalization of alkanes and alkylation-initiated radical 1,2-aryl migration in α,α-diaryl allylic alcohols using di-tert-butyl peroxide (DTBP) as the oxidant was established, which tolerates a wide range of simple alkane substrates and α,α-diaryl allylic alcohols for direct preparation of α-aryl-β-alkylated carbonyl ketones.

Metal-free oxidative C(sp3)-H bond functionalization of alkanes and conjugate addition to chromones.

A metal-free oxidative C(sp(3))-H bond functionalization and subsequent conjugate addition reaction using di-tert-butyl peroxide (DTBP) as the oxidant was established, which tolerates a wide range of simple alkane substrates to react with different substituted chromones for direct preparation of 2-alkylchromanones.

Cu-catalyzed C(sp³)-H bond activation reaction for direct preparation of cycloallyl esters from cycloalkanes and aromatic aldehydes.

Cu-catalyzed dehydrogenation-olefination and esterification of C(sp(3))-H bonds of cycloalkanes with TBHP as an oxidant has been developed. The reaction involves four C-H bond activations and gives cycloallyl ester products directly from cycloalkanes and aromatic aldehydes.

Iron-catalyzed cross-dehydrogenative coupling esterification of unactive C(sp3)-H bonds with carboxylic acids for the synthesis of α-acyloxy ethers.

An iron-catalyzed oxidative esterification reaction between unactivated C(sp(3))-H bonds from symmetric and asymmetric ethers and carboxylic acids using di-tert-butyl peroxide (DTBP) as the oxidant via a cross dehydrogenative coupling (CDC) reaction was established, which tolerates a wide range of cyclic ether substrates to react with aromatic acids and phenylacetic acid, providing an efficient method for the preparation of α-acyloxy ethers with good to excellent yields. Intermolecular competing kinetic isotope effect (KIE) experiments were also carried out, which indicate that C(sp(3))-H bond cleavage may be the rate-determining step of this CDC reaction.

Synthesis of dithieno[2,3-b:4',3'-d]siloles and their selective bromination.

The efficient synthesis of novel unsymmetrical dithienosiloles, 7,7-dimethyl-4,6-di(trimethylsilyl)-dithieno[2,3-b:4',3'-d]silole (1) and 7,7-dimethyl-2,4,6-tri(trimethylsilyl)-dithieno[2,3-b:4',3'-d]silole (2) has been developed by intramolecular silole formation with 4,4'-dibromo-2,2',5,5'-tetrakis(trimethylsilyl)-[3,3']bithienyl (3) as the starting material in the presence of t-BuLi. Upon treatment with N-bromosuccinimide (NBS) under controlled conditions, dithieno[2,3-b:4',3'-d]silole was selectively brominated to produce mono-, di-, and tribrominated dithieno[2,3-b:4',3'-d]siloles in good yields. The crystal structures of the title compounds are described.