Diastereoselective Spirocyclization of Cyclic N-Sulfonyl Ketimines with Nitroalkenes via Iridium-Catalyzed Redox-Neutral Cascade Reaction

Organic Letters, Journal Year: 2019, Volume and Issue: 21(7), P. 2056 - 2059

Published: Feb. 21, 2019

An Ir(III)-catalyzed [3 + 2] annulation of weakly coordinating N-sulfonyl ketimines with challenging α, β-unsaturated nitro olefins has been achieved via redox-neutral C-H functionalization in the presence a catalytic amount silver hexafluoroantimonate. The generation three consecutive stereogenic centers single step direct is prime feature this methodology. A wide array pharmaceutically relevant nitro-substituted spirocyclic benzosultams was synthesized good to excellent diastereoselectivity as well high yield starting from easily accessible substrates.

Language: Английский

---

Diastereoselective Spirocyclization of Benzoxazines with Nitroalkenes via Rhodium-Catalyzed C–H Functionalization/Annulation Cascade under Mild Conditions

Organic Letters, Journal Year: 2020, Volume and Issue: 22(4), P. 1340 - 1344

Published: Jan. 30, 2020

A Rh(III)-catalyzed [3 + 2] annulation of benzoxazines with nitroolefins that proceeds via redox-neutral C-H functionalization has been demonstrated, leading to the novel class spirocycles in a single step. The construction three continuous stereogenic centers achieved starting from easily accessible achiral substrates an atom-efficient manner under mild reaction conditions. broad range pharmaceutically relevant nitro substituted spirocyclic 2,3-dihydro-1,4-benzoxazine derivatives synthesized good excellent yields high diastereoselectivity.

Language: Английский

---

Recent advances in selective mono-/dichalcogenation and exclusive dichalcogenation of C(sp²)–H and C(sp³)–H bonds

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 22(4), P. 645 - 681

Published: Dec. 23, 2023

Organochalcogen compounds are prevalent in numerous natural products, pharmaceuticals, agrochemicals, polymers, biological molecules and synthetic intermediates. Direct chalcogenation of C-H bonds has evolved as a step- atom-economical method for the synthesis chalcogen-bearing compounds. Nevertheless, direct severely lags behind C-C, C-N C-O bond formations. Moreover, compared with monochalcogenation, reports selective mono-/dichalcogenation exclusive dichalcogenation relatively scarce. The past decade witnessed significant advancements various C(sp

Language: Английский

---

Ruthenium Catalyzed C–H Selenylations of Aryl Acetic Amides and Esters via Weak Coordination

Organic Letters, Journal Year: 2019, Volume and Issue: 21(16), P. 6310 - 6314

Published: Aug. 5, 2019

An efficient ruthenium-catalyzed direct C-H selenylation of aryl acetic amides and esters has been achieved via distal weakly coordination. Notable features this protocol including broad substrate scope, wide functional group tolerance, good regioselectivity. In addition, diaryl disulfides were also successfully applied to reaction under slightly modified conditions.

Language: Английский

---

Copper-catalyzed ortho-selective direct sulfenylation of N-aryl-7-azaindoles with disulfides

Organic & Biomolecular Chemistry, Journal Year: 2021, Volume and Issue: 19(13), P. 2901 - 2906

Published: Jan. 1, 2021

A copper-catalyzed direct C–H chalcogenation of N-aryl-azaindoles with disulfides is described.

Language: Английский

---

One-Pot Tandem Access to Phenothiazine Derivatives from Acetanilide and 2-Bromothiophenol via Rhodium-Catalyzed C–H Thiolation and Copper-Catalyzed C–N Amination

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(9), P. 6622 - 6632

Published: April 21, 2021

A one-pot and step economic reaction involving Rh(III)-catalyzed C–H thiolation relay Cu(II)-catalyzed C–N amination of acetanilide 2-bromothiophenol is reported here, with several valuable phenothiazine products obtained. This synthesis protocol proceeds from easily starting materials, demonstrating high atom economy, broad substrate scope, good yield. Furthermore, the directing group can be eliminated, chlorpromazine provided in a large scale; thus this could utilized to construct scaffolds.

Language: Английский

---

Exploiting Coordination Behavior of 7‐Azaindole for Mechanistic Investigation of Chan‐Lam Coupling and Application to 7‐Azaindole Based Pharmacophores

Chemistry - A European Journal, Journal Year: 2022, Volume and Issue: 29(16)

Published: Dec. 13, 2022

Abstract Multiple spectroscopic techniques, along with single‐crystal X‐ray analysis, have been used to reveal the detailed structural and electronic information on reaction intermediates of a new copper(II)‐DBU catalytic system for N‐arylation 7‐Azaindole. The mixture Chan‐Lam cross‐coupling yields two dimeric copper(II)‐7‐azaindole complexes, including one attached DBU, prior adding arylboronic acid are confirmed structurally spectroscopically. A suitable mechanism has proposed using copper(II) complex as catalyst coupling reactions. role DBU base also an auxiliary ligand in course established. transmetalated monomeric aryl‐copper(II) species generated from unit is oxidized by another equivalent yield aryl‐copper(III) intermediate facile N‐arylation, which authenticated UV‐vis spectroscopy. regeneration copper(II)‐catalyst aerial oxidation colorless copper(I) (generated via reductive elimination disproportionation step) mass absorption Detailed DFT TD‐DFT calculations help rationalize their corresponding transitions. Moreover, confirmation copper(I)‐7‐azaindole HRMS reaffirmed involvement Cu(II)/Cu(III)/Cu(I) type coupling. medicinally‐important 7‐azaindole‐based SHP2 inhibitor synthesized sequential arylation.

Language: Английский

---

Nickel(ii)-catalyzed C(sp²)–H sulfuration/annulation with elemental sulfur: selective access to benzoisothiazolones

Organic & Biomolecular Chemistry, Journal Year: 2019, Volume and Issue: 17(20), P. 5029 - 5037

Published: Jan. 1, 2019

The first Ni(ii)-catalyzed direct sulfuration/annulation of C(sp²)–H bonds with elemental sulfur was developed to afford structurally diverse benzoisothiazolones benzimidazole skeletons in high yields.

Language: Английский

---

Iron(iii) chloride-promoted cyclization of α,β-alkynic tosylhydrazones with diselenides: synthesis of 4-(arylselanyl)-1H-pyrazoles

Organic & Biomolecular Chemistry, Journal Year: 2020, Volume and Issue: 18(10), P. 1987 - 1993

Published: Jan. 1, 2020

A highly efficient iron(iii) chloride-promoted cyclization between α,β-alkynic tosylhydrazones and diselenides to form a 4-(arylselanyl)-1H-pyrazole skeleton is studied.

Language: Английский

---

Palladium‐Catalyzed Distal C−H Selenylation of 2‐Aryl Acetamides with Diselenides and Selenyl Chlorides

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 362(24), P. 5708 - 5715

Published: Oct. 27, 2020

Abstract A convenient and effective method of palladium‐catalyzed C−H selenylation the 2‐aryl acetamides assisted with removable 8‐aminoquinoline readily available diselenides selenyl chlorides has been developed. This reaction is scalable tolerates a wide range functional groups, providing straightforward way preparing unsymmetrical diaryl selenides dibenzoselene‐pinone. Preliminary mechanistic studies indicated that single‐electron transfer type mechanism facile metalation are operative. magnified image

Language: Английский

---