1401896-86-3

Upstream product

• 503-30-0 trimethylene oxide 
• 38274-16-7 2-bromo-1-(trimethylsilylethynyl)benzene 
• 15115-58-9 3-(2-bromophenyl)propionic acid 
• 52221-92-8 3-(2-bromo-phenyl)-propan-1-ol 
• 1066-54-2 trimethylsilylacetylene 
• 583-55-1 1-Bromo-2-iodobenzene 

Downstream Products

• 1239085-99-4 3-(2-ethynylphenyl)propan-1-ol 
• 1622092-50-5 3-(2-ethynylphenyl)propyl 4-bromobenzenesulfonate 

Relevant academic research and scientific papers

Remote sp2C-H Carboxylation via Catalytic 1,4-Ni Migration with CO2

A remote catalytic reductive sp2 C-H carboxylation of arenes with CO2 (1 bar) via 1,4-Ni migration is disclosed. This protocol constitutes the first catalytic 1,4-Ni migration reported to date, thus offering new vistas in the Ni-catalyzed reductive coupling arena while providing an unconventional new platform for incorporating electrophilic sites at remote sp2 C-H linkages.

Efficient endo Cycloisomerization of Terminal Alkynols Catalyzed by a New Ruthenium Complex with 8-(Diphenylphosphino)quinoline Ligand and Mechanistic Investigation

Several new ruthenium complexes supported by the P,N-donor ligand 8-(diphenylphosphino)quinoline (DPPQ) were synthesized, including [RuCl2(DPPQ)2] (1), [Ru(μ-Cl)(DPPQ)2]2(BPh4)2 (2), and [RuCl(DPPQ)2Py](BF4) (3). Complex 2, with only 1 mol % loading, was found to be catalytically active for the endo cycloisomerization of various terminal alkynols to endo-cyclic enol ethers in moderate to excellent yields. In particular, the 7- and 8-endo heterocyclization can be achieved efficiently to give the seven-membered 3-benzoxepine and eight-membered 3-benzo[d]oxocine derivatives. The stoichiometric reactions of 2 with various alkynol substrates have been carried out to investigate the mechanism, which led to a series of seven-, six-, and five-membered oxacyclocarbene ruthenium complexes including [RuCl(DPPQ)2{=CCH2C6H4CH2CH2O}](BPh4) (12) and [RuCl(DPPQ)2{=CCH2(CH2)nCH2O}](BPh4) (n=3, 12′; n=2, 13; n=1, 14). The quantitative transformation of oxacyclocarbene 12 into catalyst 2 and 3-benzoxepine 5 a as well as the efficient catalytic activity of 12 for the endo-cyclization of 2-(2-ethynylphenyl)ethanol (4 a) demonstrated that 12 is a key intermediate involved in the catalytic cycle. Moreover, comparative studies on the modeling reactions and catalytic activity of the series of oxacyclocarbene complexes indicated that the different catalytic activity of 2 for the endo-cycloisomerization of different types of alkynols can be related to the reactivity of the respective ruthenium oxacyclocarbene intermediates.

Cyclization of gold acetylides: Synthesis of vinyl sulfonates via gold vinylidene complexes

Differently substituted terminal alkynes that bear sulfonate leaving groups at an appropriate distance were converted in the presence of a propynyl gold(I) precatalyst. After initial formation of a gold acetylide, a cyclization takes place at the β-carbon atom of this species. Mechanistic studies support a mechanism that is related to that of dual gold-catalyzed reactions, but for the new substrates, only one gold atom is needed for substrate activation. After formation of a gold vinylidene complex, which forms a tight contact ion pair with the sulfonate leaving group, recombination of the two parts delivers vinyl sulfonates, which are valuable targets that can serve as precursors for cross-coupling reactions, for example. Gold vinylidene intermediates are generated by the cyclization of gold acetylides that carry a sulfonate leaving group. This result demonstrates for the first time that the formation of these species is not restricted to a dual activation mode. The cyclization products obtained herein contain a vinyl sulfonate moiety, which makes them useful building blocks for cross-coupling reactions.

Osmium-catalyzed 7-endo heterocyclization of aromatic alkynols into benzoxepines

[Figure Presented] The wizard of Os: Regioselective osmiumcatalyzed 7-endo heterocyclization of aromatic alkynols affords benzoxepines in good yields. The proposed catalytic cycle involves the key formation of osmiumvinylidene complexes via an alkynyl-hydride-osmium(IV) complex from the starting alkynol.