Copper(II) Catalyzed Expeditious Synthesis of Furoquinoxalines through a One-Pot Three-Component Coupling Strategy

Microwave assisted one-pot transformation has been developed for the synthesis of biologically significant polysubstituted furoquinoxalines in good to excellent yields through a copper­(II) catalyzed three-component coupling of <i>o-</i>phenylene­diamine, ethyl­glyoxalate, and terminal alkyne, known as A³-coupling, followed by 5<i>-endo-dig</i> cyclization

Decarbethoxylative Arylation Employing Arynes: A Metal-Free Pathway to Arylfluoroamides

An efficient, metal-free decarbethoxylative arylation protocol for the synthesis of α-aryl-α-fluoroamides from fluoromalonamates, under ambient reaction conditions using aryne as an electrophilic arylating agent, is reported. This decarbethoxylative arylation proceeds under mild conditions and provides a practical and effective entry to a wide range of α-aryl-α-fluoroacetamides. Interestingly, the use of the <i>tert</i>-butyl ester of fluoromalonamate prevented the otherwise rapid decarboxylation step, affording the arylated fluoromalonamate in moderate yield

Molecular Iodine Promoted Divergent Synthesis of Benzimidazoles, Benzothiazoles, and 2‑Benzyl-3-phenyl-3,4-dihydro‑2<i>H</i>‑benzo[<i>e</i>][1,2,4]thiadiazines

An unprecedented formation of a new class of 2-benzyl-3-phenyl-3,4-dihydro-2<i>H</i>-benzo­[<i>e</i>]­[1,2,4]­thiadiazines has been discovered during the course of benzimidazole and benzothiazole synthesis, through the molecular iodine-mediated oxidative cyclization with a new C–N and S–N bond formation at ambient temperature

Metal-Free Three-Component Domino Approach to Phosphonylated Triazolines and Triazoles

An efficient, three-component domino reaction between aldehydes, amines, and the Bestmann–Ohira reagent is reported that enables a general, mild, and straightforward access to 1,4,5-trisubstituted 1,2,3-triazolines and triazoles. The reaction proceeds through a domino-condensation/1,3-dipolar cycloaddition sequence to afford the triazoline derivatives with excellent diastereoselectivity. Moreover, when both amine and aldehyde employed for this reaction are aromatic, a spontaneous oxidation afforded 1,4,5-trisubstituted triazoles in moderate yields

Access to the Phosphorylindenopyrazole Scaffold via a Metal-Free Domino Reaction of Diazoalkylphosphonates with 3‑Bromophthalides

A novel strategy is reported here for the synthesis of an indenopyrazole scaffold bearing a phosphonate group. The entire sequence includes nucleophilic addition–elimination, Seyferth–Gilbert homologation, transphosphorylation, and a 1,3-dipolar cycloaddition reaction of diazoalkylphosphonates in a perfect “domino” manner

Silver(I)-Catalyzed Regioselective Construction of Highly Substituted α‑Naphthols and Its Application toward Expeditious Synthesis of Lignan Natural Products

A novel route has been developed for regioselective synthesis of highly substituted α-naphthols, binaphthols, and anthracenol through silver­(I) catalyzed C­(sp³)–H/C­(sp)–H, C­(sp²)–H/C­(sp)–H functionalization of β-ketoesters and alkynes, respectively, in a single step using water as a solvent. This protocol exhibited broad substrate scope and paved the way for synthesis of anticancer arylnaphthalene lignan natural products such as diphyllin, taiwanin E, and justicidin A with excellent selectivity

Decarbethoxylative Arylation Employing Arynes: A Metal-Free Pathway to Arylfluoroamides

An efficient, metal-free decarbethoxylative arylation protocol for the synthesis of α-aryl-α-fluoroamides from fluoromalonamates, under ambient reaction conditions using aryne as an electrophilic arylating agent, is reported. This decarbethoxylative arylation proceeds under mild conditions and provides a practical and effective entry to a wide range of α-aryl-α-fluoroacetamides. Interestingly, the use of the <i>tert</i>-butyl ester of fluoromalonamate prevented the otherwise rapid decarboxylation step, affording the arylated fluoromalonamate in moderate yield

An Approach to a Bislactone Skeleton: A Scalable Total Synthesis of (±)-Penifulvin A

An efficient and scalable total synthesis of the architecturally challenging sesquiterpenoid (±)-penifulvin A has been accomplished via a 12-step sequence with an overall yield of 16%. For the construction of this structurally complex tetracyclic molecule, the key steps used included 1,4-conjugate addition, a Pd(0) catalyzed cross-coupling reaction between an enol phosphate and trimethyl aluminum, Claisen rearrangement using the Johnson orthoester protocol, Ti­(III)-mediated reductive epoxide opening–cyclization, Lewis acid catalyzed epoxy-aldehyde rearrangement, and finally a substrate controlled oxidative cascade lactonization process

Access to the Phosphorylindenopyrazole Scaffold via a Metal-Free Domino Reaction of Diazoalkylphosphonates with 3‑Bromophthalides

A novel strategy is reported here for the synthesis of an indenopyrazole scaffold bearing a phosphonate group. The entire sequence includes nucleophilic addition–elimination, Seyferth–Gilbert homologation, transphosphorylation, and a 1,3-dipolar cycloaddition reaction of diazoalkylphosphonates in a perfect “domino” manner

Leveraging Zn(II) Catalyst: Synthesis of Amidoquinolines via (3 + 3) Heteroannulation of Aromatic Amines and Ynamides

Herein, we present a Zn­(II)-catalyzed (3 + 3) heteroannulation reaction between aromatic amines and 1,3-diynamides for the synthesis of amidoquinolines. A large number of aromatic amines are well tolerated, furnishing quinoline derivatives in up to excellent yield. Notably, various reactive functional groups have survived under the optimal reaction conditions, highlighting the mildness of the developed protocol. In addition, amines derived from bioactive molecules show modest reactivity