16002-93-0Relevant articles and documents
Saturation transfer and chemical exchange measurements of the stereochemical drift occurring during the Wittig reaction
Pascariu, Aurelia,Mracec, Mircea,Berger, Stefan
, p. 451 - 456 (2005)
The Wittig reaction of butylidenetriphenylphosphorane with benzaldehyde using LiHMDS as base in THF was studied. The stereochemical drift (different ratio obtained in alkenes versus oxaphosphetane intermediates) was followed by low-temperature 1D NMR tech
Effect of substituents on the thermal decomposition of diazirines: Experimental and computational studies
Liu, Michael T. H.,Choe, Yoong-Kee,Kimura, Masahiro,Kobayashi, Kaoru,Nagase, Shigeru,Wakahara, Takatsugu,Niino, Yasuyuki,Ishitsuka, Midori O.,Maeda, Yutaka,Akasaka, Takeshi
, p. 7471 - 7478 (2003)
The thermal decomposition of phenylchlorodiazirine (1), phenyl-n-butyldiazirine (2), and 2-adamantane-2,3′-[3H]diazirine (3) has been studied in solution in the presence of C60. The C60 probe technique indicates that in the decomposition diazirine 1 yielded exclusively phenylchlorocarbene, diazirine 2 yielded mainly a diazo intermediate, and diazirine 3 yielded a mixture of carbene and diazo compound. In the case of diazirine 2, 13percent of (E)-1-phenyl-1-pentene resulted from the direct thermal rearrangement of diazirine without the participation of a carbene. As well, the thermal decomposition of these diazirines has been studied theoretically with ab initio and density functional methods. The experimental results are broadly in agreement with the theoretical predictions. The calculations further indicate that the rebound reaction between carbene and molecular nitrogen leading to the formation of a diazo intermediate is an important reaction in the gas-phase decomposition of diazirine.
Synthesis of Functionalized Heteroaromatics: Application to Formal Total Synthesis of Camptothecin
Murata, Naoko,Sugihara, Takumichi,Kondo, Yoshinori,Sakamoto, Takao
, p. 298 - 300 (1997)
The formal total synthesis of camptothecin was achieved via two types of lithiation reactions of pyridine derivatives and a Pd-catalyzed carbonylation of pyridylmethyl methanesulfonates.
Pd-catalyzed coupling reaction of allyl and propargyl ethers with chlorosilanes
Naitoh, Yoshitaka,Bando, Fumiaki,Terao, Jun,Otsuki, Kazutaka,Kuniyasu, Hitoshi,Kambe, Nobuaki
, p. 236 - 237 (2007)
Pd-catalyzed synthesis of allylsilanes from chlorosilanes and allyl ethers is described. The reaction proceeds efficiently at room temperature by the use of phenyl or vinyl Grignard reagent in the presence of palladium catalysts. The present method can also be applied to synthesis of propargylsilanes by the use of propargyl ethers. Copyright
Solventless Suzuki coupling reactions on palladium-doped KF/Al2O3
Kabalka, George W.,Pagni, Richard M.,Hair, C. Maxwell
, p. 1423 - 1425 (1999)
(equation presented) A solventless Suzuki coupling has been developed. A commercially available potassium fluoride-alumina mixture is utilized along with palladium black.
Unexpected 1,5-dilithiation of chiral o-TMS blocked (dimethylamino) phenylmethylferrocene: An alternative approach to chiral ferrocenyl 1,5-diphosphanes
Fukuzawa, Shin-Ichi,Yamamoto, Masahisa,Kikuchi, Satoshi
, p. 1514 - 1517 (2007)
(Chemical Equation Presented) The 1,5-dilithiation of o-TMS blocked (dimethylamino)phenylmethylferrocene 4 unexpectedly occurred even though one equimolar amount of t-BuLi was used and the 1,5-dilithiated ferrocene 6 was trapped by iodine followed by remo
Enantioselective copper-catalyzed SN2' substitution with Grignard reagents
Alexakis,Malan,Lea,Benhaim,Fournioux
, p. 927 - 930 (2001)
Cinnamyl chlorides undergo selective SN2' allylic substitution by Grignard reagents using catalytic amount (1 mol%) of CuCN and 1-2 mol% trivalent phosphorus ligand, in dichloromethane. With chiral phosphorus ligands derived from TADDOL ee's up
Ready approach to poly(vinyldiphenylphosphine): A novel soluble polymer for conveniently conducting Wittig reactions
Ye, Jing-Jing,Han, Li-Biao
supporting information, (2021/01/25)
The novel poly(vinyldiphenylphosphine) could be easily prepared by using the reactions of the cheap poly(vinyl chloride) with sodium phosphides. Poly(vinyldiphenylphosphine) is soluble in common solvents while its corresponding phosphine oxide is hardly soluble in the solvents. Taking advantage of this different solubility, poly(vinyldiphenylphosphine) could be used as a soluble phosphinopolymer for the Wittig reactions. The reactions could take place efficiently to produce the corresponding olefins while the isolation of the products were simple since the resulted poly(vinyldiphenylphosphine oxide) was not soluble in the solvent and could be easily removed by filtration.
Electro-mediated PhotoRedox Catalysis for Selective C(sp3)–O Cleavages of Phosphinated Alcohols to Carbanions
Barham, Joshua P.,K?nig, Burkhard,Karl, Tobias A.,Reiter, Sebastian,Tian, Xianhai,Yakubov, Shahboz,de Vivie-Riedle, Regina
supporting information, p. 20817 - 20825 (2021/08/18)
We report a novel example of electro-mediated photoredox catalysis (e-PRC) in the reductive cleavage of C(sp3)?O bonds of phosphinated alcohols to alkyl carbanions. As well as deoxygenations, olefinations are reported which are E-selective and can be made Z-selective in a tandem reduction/photosensitization process where both steps are photoelectrochemically promoted. Spectroscopy, computation, and catalyst structural variations reveal that our new naphthalene monoimide-type catalyst allows for an intimate dispersive precomplexation of its radical anion form with the phosphinate substrate, facilitating a reactivity-determining C(sp3)?O cleavage. Surprisingly and in contrast to previously reported photoexcited radical anion chemistries, our conditions tolerate aryl chlorides/bromides and do not give rise to Birch-type reductions.
Heterogeneous Isomerization for Stereoselective Alkyne Hydrogenation to trans-Alkene Mediated by Frustrated Hydrogen Atoms
Zhang, Weijie,Qin, Ruixuan,Fu, Gang,Zheng, Nanfeng
supporting information, p. 15882 - 15890 (2021/10/02)
Stereoselective production of alkenes from the alkyne hydrogenation plays a crucial role in the chemical industry. However, for heterogeneous metal catalysts, the olefins in cis-configuration are usually dominant in the products due to the most important and common Horiuti-Polanyi mechanism involved over the metal surface. In this work, through combined theoretical and experimental investigations, we demonstrate a novel isomerization mechanism mediated by the frustrated hydrogen atoms via the H2 dissociation at the defect on solid surface, which can lead to the switch in selectivity from the cis-configuration to trans-configuration without overhydrogenation. The defective Rh2S3 with exposing facet of (110) exhibits outstanding performance as a heterogeneous metal catalyst for stereoselective production of trans-olefins. With the frustrated hydrogen atoms at spatially separated high-valence Rh sites, the isolated hydrogen mediated cis-to-trans isomerization of olefins can be effectively conducted and the overhydrogenation can be completely inhibited. Furthermore, the bifunctional Rh-S/Pd nanosheets have been synthesized through the surface modification of Pd nanosheets with rhodium and sulfide. With the selective semihydrogenation of alkynes into cis-olefins catalyzed by the small surface PdSx ensembles, the bifunctional Rh-S/Pd nanosheets exhibit excellent activity and stereoselectivity in the one-pot alkyne hydrogenation into trans-olefin, which surpasses the most reported homogeneous and heterogeneous catalysts.
