54731-58-7Relevant academic research and scientific papers
Highly active and selective semihydrogenation of alkynes with the palladium nanoparticles-tetrabutylammonium borohydride catalyst system
Hori, Junichi,Murata, Kunihiko,Sugai, Toshiki,Shinohara, Hisanori,Noyori, Ryoji,Arai, Noriyoshi,Kurono, Nobuhito,Ohkuma, Takeshi
, p. 3143 - 3149 (2009)
Palladium nanoparticles are prepared from palladium(II) acetate and 2 equivalents of potassium tert-butoxide in the presence of 4-octyne. The palladium nanoparticles-tetrabutylammonium borohydride system shows excellent catalytic activity and selectivity in the semihydrogenation of alkynes to the [(Z)-]alkenes. The hydrogenation of 4-octyne is conducted with the catalyst system at a substrate-to-palladium molar ratio of 10,000-200,000 under 8 atm of hydrogen to give (Z)-4-octene in > 99% yield. Isomerization and over-reduction of the Z-alkene are very slow even after consumption of the alkyne.
Stereoselective Chromium-Catalyzed Semi-Hydrogenation of Alkynes
Gregori, Bernhard J.,Nowakowski, Michal,Schoch, Anke,P?llath, Simon,Zweck, Josef,Bauer, Matthias,Jacobi von Wangelin, Axel
, p. 5359 - 5363 (2020/09/03)
Chromium complexes have found very little applications as hydrogenation catalysts. Here, we report a Cr-catalyzed semi-hydrogenation of internal alkynes to the corresponding Z-alkenes with good stereocontrol (up to 99/1 for dialkyl alkynes). The catalyst comprises the commercial reagents chromium(III) acetylacetonate, Cr(acac)3, and diisobutylaluminium hydride, DIBAL?H, in THF. The semi-hydrogenation operates at mild conditions (1-5 bar H2, 30 °C).
Stereoselective Alkyne Hydrogenation by using a Simple Iron Catalyst
Gregori, Bernhard J.,Schwarzhuber, Felix,P?llath, Simon,Zweck, Josef,Fritsch, Lorena,Schoch, Roland,Bauer, Matthias,Jacobi von Wangelin, Axel
, p. 3864 - 3870 (2019/07/31)
The stereoselective hydrogenation of alkynes constitutes one of the key approaches for the construction of stereodefined alkenes. The majority of conventional methods utilize noble and toxic metal catalysts. This study concerns a simple catalyst comprised of the commercial chemicals iron(II) acetylacetonate and diisobutylaluminum hydride, which enables the Z-selective semihydrogenation of alkynes under near ambient conditions (1–3 bar H2, 30 °C, 5 mol % [Fe]). Neither an elaborate catalyst preparation nor addition of ligands is required. Mechanistic studies (kinetic poisoning, X-ray absorption spectroscopy, TEM) strongly indicate the operation of small iron clusters and particle catalysts.
Synthesis of (E)-alkenes via hydroindation of C{triple bond, long}C in InCl3-NaBH4 system
Wang, Chunyan,Yan, Lei,Zheng, Zhiguo,Yang, Deyu,Pan, Yuanjiang
, p. 7712 - 7717 (2007/10/03)
In InCl3-NaBH4-MeCN system, terminal aryl alkynes could couple with aryl iodides and bromides to give disubstituted alkenes via hydroindation of C{triple bond, long}C. In the similar way, (E)-alkenylsilanes were synthesized via reduction of alkynylsilanes in tetrahydrofuran (THF) in high yields. The processes showed high regio- and stereoselectivity.
Simple preparation of α-bromo acyl silanes α-ketoacyl silanes and α-ketoesters from silyl acetylenes
Bulman Page, Philip C.,Rosenthal, Stephen
, p. 2573 - 2586 (2007/10/02)
α-Bromo- and α-keto-acyl silanes may simply and efficiently be prepared in short reaction schemes from silyl acetylenes; α-ketoacyl silanes are also implicated in a one-pot synthesis of α-ketoesters from silyl acetylenes.
PALLADIUM-CATALYZED REACTIONS OF TRIALKYLSTANNYL PHENYL SULFIDES WITH ALKENYL BROMIDES. A NEW DIASTEREOSELECTIVE SYNTHESIS OF (E)-1-ALKENYL PHENYL SULFIDES
Carpita, Adriano,Rossi, Renzo,Scamuzzi, Barbara
, p. 2699 - 2702 (2007/10/02)
The reaction of easily available stereoisomeric mixtures of 1-alkenyl bromides with molar excesses of trialkylstannyl phenyl sulfides takes place readily in the presence of Pd(PPh3)4 to afford diastereoselectively (E)-1-alkenyl phenyl sulfides in excellent yields.
Highly Stereoselective Synthesis of Vinylsilanes from Carbonyl Compounds
Barluenga, Jose,Fernandez-Simon, Jose L.,Concellon, Jose M.,Yus, Miguel
, p. 234 - 236 (2007/10/02)
The in situ generated (chlorolithiomethyl)trimethylsilane reacts at -60 deg C to -45 deg C with different aldehydes or ketones 1 to afford, after lithation with lithium naphthalenide at -78 deg C to 20 deg C, vinylsilanes 5a-h in a stereoselective manner.
(E)- and (Z)-(1-Iodo-1-alkenyl)silanes. Their Preparation and Their Conversion ino (E)- and (Z)-(1-Lithio-1-alkenyl)silanes
Zweifel, George,Murray, Rex E.,On, Harry P.
, p. 1292 - 1295 (2007/10/02)
(Z)-(1-Iodo-1-alkenyl)trimethylsilanes can be conveniently obtained by isomerization of the readily available E isomers through the intermediacy of (1-lithioalkenyl)silanes formed by addition of catalytic amounts of tert-butyllithium.Reaction of (E)- and
