183589-09-5

Upstream product

• 32865-61-5 2-iodophenyl acetate 
• 536-74-3 phenylacetylene 
• 1829-37-4 o-bromophenyl acetate 
• 50-78-2 aspirin 
• 2170-06-1 1-Phenyl-2-(trimethylsilyl)acetylene 

Downstream Products

• 1191950-62-5 2-(phenyl)-3-(phenylsulfanyl)benzo[b]furan 
• 37883-72-0 2-phenylbenzo[b]furan-3-carbonitrile 
• 92104-01-3 2-phenyl-3-bromobenzo[b]furan 
• 246230-86-4 3-iodo-2-phenylbenzo[b]furan 
• 1839-72-1 2-phenylbenzofuran 
• 1310802-25-5 C₁₆H₁₆O₃ 
• 1581275-98-0 C₂₀H₁₃BO₃ 
• 1581275-99-1 2-(2-phenylbenzofuran-3-yl)benzo[d][1,3,2]dioxaborole 
• 1581276-22-3 C₁₉H₁₆BNO₅ 
• 4265-21-8 3-acetyl-2-phenylbenzofuran 
• 200941-12-4 Bromo-acetic acid 2-phenylethynyl-phenyl ester 
• 13448-97-0 methyl 2-phenylbenzofuran-3-carboxylate 
• 92151-73-0 2-phenylethynylphenol 

Relevant academic research and scientific papers

Palladium-catalyzed decarbonylative sonogashira coupling of terminal alkynes with carboxylic acids

A direct decarbonylative Sonogashira coupling of terminal alkynes with carboxylic acids was achieved through palladium catalysis. This reaction did not use overstoichiometric oxidants, thus overcoming the homocoupling issue of terminal alkynes. Under the reaction conditions, a wide range of carboxylic acids including those bioactive ones could couple readily with various terminal alkynes, thus providing a relative general method for preparing internal alkynes.

Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes: Synthesis of unsymmetrical diarylethynes

Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes is described. This reaction not only effectively inhibits the formation of undesired homocoupled products by avoiding the addition of a base, but also exhibits a wide substrate scope to provide a general access to diverse unsymmetrical diarylethynes.

Alkoxyboration: Ring-closing addition of B-O σ bonds across alkynes

For nearly 70 years, the addition of boron-X σ bonds to carbon-carbon multiple bonds has been employed in the preparation of organoboron reagents. However, the significantly higher strength of boron-oxygen bonds has thus far precluded their activation for addition, preventing a direct route to access a potentially valuable class of oxygen-containing organoboron reagents for divergent synthesis. We herein report the realization of an alkoxyboration reaction, the addition of boron-oxygen σ bonds to alkynes. Functionalized O-heterocyclic boronic acid derivatives are produced using this transformation, which is mild and exhibits broad functional group compatibility. Our results demonstrate activation of this boron-O σ bond using a gold catalysis strategy that is fundamentally different from that used previously for other boron addition reactions.

Expanded-ring N-heterocyclic carbenes efficiently stabilize gold(I) cations, leading to high activity in π-acid-catalyzed cyclizations

A series of six- and seven-membered expanded-ring N-heterocyclic carbene (er-NHC) gold(I) complexes has been synthesized using different synthetic approaches. Complexes with weakly coordinating anions [(er-NHC)AuX] (X -=BF4-, NTf2-, OTf -) were generated in solution. According to their 13C NMR spectra, the ionic character of the complexes increases in the order X -=Cl-2--4-. Additional factors for stabilization of the cationic complexes are expansion of the NHC ring and the attachment of bulky substituents at the nitrogen atoms. These er-NHCs are bulkier ligands and stronger electron donors than conventional NHCs as well as phosphines and sulfides and provide more stabilization of [(L)Au+] cations. A comparative study has been carried out of the catalytic activities of five-, six-, and seven-membered carbene complexes [(NHC)AuX], [(Ph3P)AuX], [(Me2S)AuX], and inorganic compounds of gold in model reactions of indole and benzofuran synthesis. It was found that increased ionic character of the complexes was correlated with increased catalytic activity in the cyclization reactions. As a result, we developed an unprecedentedly active monoligand cationic [(THD-Dipp)Au]BF4 (1,3-bis(2,6-diisopropylphenyl) -3,4,5,6-tetrahydrodiazepin-2-ylidene gold(I) tetrafluoroborate) catalyst bearing seven-membered-ring carbene and bulky Dipp substituents. Quantitative yields of cyclized products were attained in several minutes at room temperature at 1 mol% catalyst loadings. The experimental observations were rationalized and fully supported by DFT calculations. What a difference a ring makes: Expanded-ring N-heterocyclic carbenes (er-NHC) surpass their five-membered ring counterparts, as well as Ph3P and Me2S, in the stabilization of cationic gold(I) species due to increased steric protection and electron-donating properties. A monoligand cationic [(THD-Dipp)Au]BF 4 (Dipp=2,6-diisopropylphenyl) complex bearing a seven-membered ring carbene and bulky Dipp substituents exhibits unprecedentedly high catalytic activity in indole and benzofuran synthesis (see scheme).

A concise route to dihydrobenzo[b]furans: Formal total synthesis of (+)-lithospermic acid

A sequence of Sonogashira coupling, Pd(II)-catalyzed carbonylative annulation, and benzofuran reduction (Mg, MeOH, NH4Cl) provides a convergent and modular synthetic route to trans-2-aryl-2,3-dihydrobenzo[b]furan- 3-carboxylates, which are a structural feature of numerous biologically active natural products. This versatile strategy was applied to the formal total synthesis of the anti-HIV natural product (+)-lithospermic acid.

Efficient synthesis of 5-nitro-benzo[b]furans via 2-bromo-4-nitro-phenyl acetates

Acetylation/Sonogashira cross-coupling reaction/cyclization has been carried out in one-pot using a Na2PdCl4/2-(di-tert-butylphosphino)-N-phenylindole/CuI system in TMEDA to give 5-nitro-2-substituted benzo[b]furans in excellent yields. We also describe the extension of this method to 4-EWG-2-bromo-phenols obtaining 2,5-disubstituted-benzo[b]furans in good yields.

Copper-mediated cyclization-halogenation and cyclization-cyanation reactions of β-hydroxyalkynes and o -alkynylphenols and anilines

The CuX (X = I, Br, Cl, CN)-mediated cyclization-halogenation and cyclization-cyanation reactions of β-hydroxyalkynes and o-alkynylphenol and -aniline derivatives give rise to 3-halo- and 3-cyanofuro[3,2-b]pyrroles, 3-iodo-, 3-bromo-, and 3-cyanobenzofurans, and 3-cyanoindoles, respectively.

Synthesis of novel oxygen heterocycles: 1,10-dioxa-cyclopenta[a]fluorene and benzo[b]naphtho[2, 1-d]furans via D?tz intramolecular benzannulation

Novel fused heterocycles 1,10-dioxa-cyclopenta[a]fluorene and benzo[b]naphtho[2, 1-d]furans were synthesized via D?tz intramolecular benzannulation of alkyne tethered aryloxy chromium Fischer carbenes.

A new complex of palladium-thiourea and carbon tetrabromide catalyzed carbonylative annulation of o-hydroxylarylacetylenes: Efficient new synthetic technology for the synthesis of 2,3-disubstituted benzo[b]furans

(matrix presented) A highly effective cocatalysis system (Pdl2-thiourea and CBr4) was developed for carbonylative cyclization of both electron-rich and electron-deficient o-hydroxylarylacetylenes to the corresponding methyl benzo[b]f

Convergent total synthesis of lamellarin K

The azomethine ylide derived from dihydroisoquinolinium salt 24 undergoes an intramolecular [3 + 2] cycloaddition reaction to give pyrrole 25 which upon de-isopropylation affords the marine alkaloid lamellarin K 4.