2,3-Dihalo-1-propenes as Building Blocks in Cu(I)-Catalyzed Domino Reactions: Efficient and Selective Synthesis of Furans

The Cu­(I)-catalyzed reaction of 2,3-dibromo-1-propenes with β-ketoesters and 1,3-diketones, respectively, in DMF at 120 °C using Cs₂CO₃ as a base and hydroquinone as an additive exclusively delivers 2,3,5-trisubstituted furans and related compounds with yields up to 96%. The highly regioselective domino process is based on an intermolecular <i>C</i>-allylation followed by an intramolecular Ullmann type <i>O</i>-vinylation and a double bond isomerization

Catalytic Iodine and Morpholine as Reagent Combination for Hydration of Alkynes via Markovnikov Addition

This work describes the iodine-catalyzed N-methyl morpholine-promoted hydration of alkynes via Markovnikov type addition. The developed protocol provides a direct approach to synthesize methyl ketones under metal-free condition. A series of aromatic alkynes embedded with electron-donating and electron-withdrawing groups were well-investigated to give the corresponding products in good to high yields

C-H Functionalization and C-N Bond Formation Approaches under Catalytic Conditions for the Synthesis of α-Ketoamides and 2,4-Disubstituted-1,3,5-triazines

This work describes an easy way to perform approach for the transformation of arylmethyl ketones to α-ketoamides using secondary amines as starting materials in the presence of iodine as a catalyst in water under peroxide free reaction conditions. The established amidation reaction proceeds via α-C(sp3)-H functionalization and C-N bond formation approaches in water at ambient temperature. On the other hand, a novel and straightforward synthesis of 2,4-disubstituted-1,3,5-triazines via nickel-catalyzed cyclization of amidines with DMSO as one-carbon synthon has been developed. The developed strategy proceeds via C-N bond formation

Base-Promoted Domino Reaction of 5‑Substituted 2‑Nitrosophenols with Bromomethyl Aryl Ketones: A Transition-Metal-Free Approach to 2‑Aroylbenzoxazoles

The reaction of 5-substituted 2-nitrosophenols with bromomethyl aryl ketones and related compounds employing K₂CO₃ as a base in refluxing THF and DMF at 80 °C, respectively, delivers 2-aroylbenzoxazoles in a single step with yields up to 85%. The new method involves an intermolecular nucleophilic substitution followed by intramolecular 1,2-addition and elimination. It allows an efficient and practical access to 2-aroylbenzoxazoles under transition-metal-free conditions

Copper(I)-Catalyzed Intramolecular O‑Arylation for the Synthesis of 2,3,4,9-Tetrahydro‑1<i>H</i>‑xanthen-1-ones with Low Loads of CuCl

As little as 0.5 mol % CuCl is sufficient to catalyze the intramolecular O-arylation of easily accessible 2-(2-bromobenzyl)­cyclohexane-1,3-diones to provide the corresponding 2,3,4,9-tetrahydro-1<i>H</i>-xanthen-1-ones with yields ranging from 83% to 99%

Reaction of 1‑Nitroso-2-naphthols with α‑Functionalized Ketones and Related Compounds: The Unexpected Formation of Decarbonylated 2‑Substituted Naphtho[1,2‑<i>d</i>][1,3]oxazoles

Reactions between 1-nitroso-2-naphthols and α-functionalized ketones such as α-bromo-, α-chloro-, α-mesyloxy-, α-tosyloxy-, and α-hydroxy ketones under basic conditions delivered 2-substituted naphtho­[1,2-<i>d</i>]­[1,3]­oxazoles in a single synthetic operation. The product formation was accompanied by the unexpected loss of the CO group from the α-functionalized ketones. With aryl bromides, allyl bromides, α-bromo diketones, α-bromo cyanides, α-bromoesters, and α-bromo ketoesters as substrates the formation of naphtho­[1,2-<i>d</i>]­[1,3]­oxazoles was also observed. The transformations were performed in 1,2-dichloroethane or acetonitrile under reflux and gave the corresponding naphthoxazoles with yields ranging between 52% and 85%

Reaction of 1‑Nitroso-2-naphthols with α‑Functionalized Ketones and Related Compounds: The Unexpected Formation of Decarbonylated 2‑Substituted Naphtho[1,2‑<i>d</i>][1,3]oxazoles

Reactions between 1-nitroso-2-naphthols and α-functionalized ketones such as α-bromo-, α-chloro-, α-mesyloxy-, α-tosyloxy-, and α-hydroxy ketones under basic conditions delivered 2-substituted naphtho­[1,2-<i>d</i>]­[1,3]­oxazoles in a single synthetic operation. The product formation was accompanied by the unexpected loss of the CO group from the α-functionalized ketones. With aryl bromides, allyl bromides, α-bromo diketones, α-bromo cyanides, α-bromoesters, and α-bromo ketoesters as substrates the formation of naphtho­[1,2-<i>d</i>]­[1,3]­oxazoles was also observed. The transformations were performed in 1,2-dichloroethane or acetonitrile under reflux and gave the corresponding naphthoxazoles with yields ranging between 52% and 85%