Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• . Radical addition to the alkyne leads to the anti-Markovnikov adduct via the more stable secondary radical intermediate. As alkyne 2-methyl-3-butyn-2-ol was selected, which is easily prepared from acetylene and acetone on large scale and the respective thiol–yne adducts can be converted into valuable

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• % selectivity at 81% conversion under room temperature and 1 bar H2 (STY for 2a: 0.12 kg L−1 h−1), with no detectable signs of deactivation over 6 h reaction time [126]. 2-Methyl-3-butyn-2-ol and 3-methyl-1-pentyn-3-ol The catalytic partial hydrogenation reaction of 2-methyl-3-butyn-2-ol (3) is an in-depth

• materials, that was attributed to the enhanced mass transfer of the one-dimensional packed support [139]. It is worth noticing that this result was obtained as a consequence of the so-called “Rational Catalyst Design” approach [140], applied to the hydrogenation of 2-methyl-3-butyn-2-ol as a case study [29

• the process [180]. On the other hand, a slightly negative effect of the alkyl substituent length on the selectivity of 2-methyl-3-butyn-2-ol (3) and 3-methyl-1-pentyn-3-ol (4) alcohols hydrogenation was demonstrated, for different Pd packed catalysts under the same conditions and substrate conversion

Asymmetric 1,4-bis(ethynyl)bicyclo[2.2.2]octane rotators via monocarbinol functionalization. Ready access to polyrotors

• Cyprien Lemouchi and
• Patrick Batail

Beilstein J. Org. Chem. 2015, 11, 1881–1885, doi:10.3762/bjoc.11.202

• functional molecular rotors. Their synthesis uses carbinol, 2-methyl-3-butyn-2-ol, as a protecting group because of its polar character and its ability to sustain orthogonal functionalization with the further advantage of being readily removed. The synthesis in good yields of unprecedented asymmetric rotors

• variety of functionalization sequences of BCO rotators by performing nucleophilic reactions on the terminal alkyne [16] as well as Sonogashira coupling reactions [17]. One way to synthesize 1 is via a catalytic reaction to achieve the deprotection of a single 2-methyl-3-butyn-2-ol and transform the

Practical synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides via conventional and decarboxylative copper-free Sonogashira coupling reactions

• Andrea Caporale,
• Stefano Tartaggia,
• Andrea Castellin and
• Ottorino De Lucchi

Beilstein J. Org. Chem. 2014, 10, 384–393, doi:10.3762/bjoc.10.36

• solvent was found to be highly effective for the coupling reaction of 2-methyl-3-butyn-2-ol (4) with a wide range of aryl bromides in good to excellent yields. Analogously, the synthesis of aryl-2-methyl-3-butyn-2-ols was performed also through the decarboxylative coupling reaction of 4-hydroxy-4-methyl-2

• complicates the recycling of the palladium catalyst since the two metals are difficult to separate. Sonogashira reactions can be used for the syntheses of terminal alkynes from aryl halides through the coupling with an alkyne source such as trimethylsilylacetylene (TMSA) or 2-methyl-3-butyn-2-ol (4) in

• able to couple aryl bromides with terminal alkynes, including a couple of examples with 2-methyl-3-butyn-2-ol, in moderate yield [35]. Two simple reaction protocols for the copper-free coupling of 4 have been also reported for iodo nitroxides [30] and cyclopropyl iodides [29]. Herein, we present two

A rapid and efficient synthetic route to terminal arylacetylenes by tetrabutylammonium hydroxide- and methanol-catalyzed cleavage of 4-aryl-2-methyl-3-butyn-2-ols

• Jie Li and
• Pengcheng Huang

Beilstein J. Org. Chem. 2011, 7, 426–431, doi:10.3762/bjoc.7.55

• reaction time under much milder conditions. Keywords: 4-aryl-2-methyl-3-butyn-2-ol; deprotection reaction; 2-methyl-3-butyn-2-ol; terminal alkynes; tetrabutylammonium hydroxide; Introduction Terminal arylacetylenes are key precursors for the construction of conjugated oligo- or polyarylacetylenes, which

• [(3-cyanopropyl)dimethylsilyl]acetylene (CPDMSA), and 2-methyl-3-butyn-2-ol (MEBYNOL). The trialkylsilyl groups can be easily removed by treatment with oxygen-based nucleophiles or fluoride at ambient temperature [10][11][12]. However, trialkylsilylacetylenes are rather expensive that their use is

• Discussion Initially, we chose 4-(4-(phenylethynyl)phenyl)-2-methyl-3-butyn-2-ol (1a) as the model compound and carried out the deprotection reaction in toluene at 75 °C in the presence of inorganic bases and Bu4NOH/CH3OH, respectively (Table 1). It was found that by using inorganic bases, such as NaH, NaOH

Donor-acceptor substituted phenylethynyltriphenylenes – excited state intramolecular charge transfer, solvatochromic absorption and fluorescence emission

• Ritesh Nandy and
• Sethuraman Sankararaman

Beilstein J. Org. Chem. 2010, 6, 992–1001, doi:10.3762/bjoc.6.112

• ), PPh3 (0.15 g, 0.6 mmol), CuI (0.105 g, 0.6 mmol), degassed THF (30 mL) and diisopropylamine (30 mL). The mixture was stirred at room temperature for 15 min and 2-methyl-3-butyn-2-ol (0.32 g, 3.8 mmol) was added. Stirring was continued for 2 h at 60 °C after which time the solvent was removed and the