56667-12-0Relevant articles and documents
A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
, p. 6684 - 6690 (2021/05/31)
Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
E, Z -Selectivity in the reductive cross-coupling of two benzaldehydes to stilbenes under substrate control
Arkhypchuk, Anna I.,D'Imperio, Nicolas,Ott, Sascha
supporting information, p. 6171 - 6179 (2020/10/21)
Unsymmetrical E- and Z-stilbenes can be synthesized from two differently substituted benzaldehydes in a MesP(TMS)Li-promoted reductive coupling sequence. Depending on the order of addition of the two coupling partners, the same olefin can be produced in either E- or Z-enriched form under identical reaction conditions. A systematic study of the correlation between the stereochemical outcome of the reaction and the substitution pattern at the two aldehydes is presented. The results can be used as guidelines to predict the product stereochemistry. This journal is
Photophysical Properties of Silyl-Substituted Stilbene Derivatives
Maeda, Hajime,Horikoshi, Ryo,Yamaji, Minoru,Furuyama, Taniyuki,Segi, Masahito
supporting information, p. 3410 - 3422 (2020/06/17)
The effects of silyl groups on the structural, absorption, fluorescence, and photoisomerization properties of stilbenes were investigated. In comparison to that of the parent stilbene (1), fluorescence quantum yields (Φf) of Me3Si-substituted stilbenes 2–4 and 6 in solution were higher. Derivative 5, in which Me3Si groups are present at all ortho positions of the arene moieties, did not fluoresce at room temperature. The absorption and fluorescence wavelength maxima of Me3SiMe2Si-substituted stilbene 7 occurred at longer wavelengths compared to those of the Me3Si analog 2. The results of theoretical calculations showed that this difference is a consequence of an increase in the HOMO energy of 7 caused by orbital interaction between π-system and the σ(Si–Si) orbital. Stilbene 14, with two Me3Si-C≡C groups at both para positions, had a high Φf (0.95). The calculated transition dipole moment (μ) was well correlated with Φf. Derivative 21, which contains Ph2N and Me3SiC≡C groups exhibited solvatofluorochromism because it possesses a twisted intramolecular charge transfer (TICT) excited state in which the Ph2N group and the aromatic ring are orthogonal.
Oxidative Dephosphorylation of Benzylic Phosphonates with Dioxygen Generating Symmetrical trans-Stilbenes
Huang, Tianzeng,Chen, Tieqiao,Han, Li-Biao
, p. 2959 - 2965 (2018/03/09)
Under a dioxygen atmosphere, benzylphosphonates and related phosphoryl compounds can readily produce the corresponding trans-stilbenes in high yields with high selectivity upon treatment with bases. Various functional groups were tolerable under the reaction conditions.
Copper-catalyzed double intramolecular ullmann coupling for the synthesis of diastereomerically and enantiomerically pure 4b,9b-dihydrobenzofuro[3,2-b]benzofurans
Imrich, Hans-Georg,Conrad, Jürgen,Beifuss, Uwe
, p. 7718 - 7734 (2015/12/31)
The copper-catalyzed double intramolecular Ullmann coupling of syn-1,2-bis(2-bromoaryl)ethane-1,2-diols with catalytic amounts of CuII oxinate as the copper source, K3PO4 as a base, and KI as a reductant in aqueous acetoni
Straightforward access to chiral diol bidentate ligands: Their efficient enantioselective induction in the addition of diethylzinc to aromatic aldehydes
G?k, Yaar,Külolu, Soner,G?k, Halil Zeki,Kekec, Levent
, p. 835 - 838 (2015/02/19)
Enantiopure C2-symmetric diol bidentate ligands have been synthesized in a straightforward manner through a three-step reaction with good yields. The synthesized C2-symmetric diol bidentate ligands were used in the addition of diethylzinc to various aromatic aldehydes, a general catalytic benchmark reaction, in order to assess their enantioselective induction properties. The enantioselective addition of diethylzinc to 1-naphthaldehyde and 3-chlorobenzaldehyde was achieved with an enantiomeric excess (ee) of up to 98%. All synthesized ligands were also evaluated in the addition of diethyzinc to aromatic aldehydes including an extra metal such as Ti(IV) (up to 99% ee).
Straightforward access to chiral diol bidentate ligands: Their efficient enantioselective induction in the addition of diethylzinc to aromatic aldehydes
G?k, Ya?ar,Küloglu, Soner,G?k, Halil Zeki,Kekec?, Levent
, p. 835 - 838 (2015/04/16)
Enantiopure C2-symmetric diol bidentate ligands have been synthesized in a straightforward manner through a three-step reaction with good yields. The synthesized C2-symmetric diol bidentate ligands were used in the addition of diethylzinc to various aromatic aldehydes, a general catalytic benchmark reaction, in order to assess their enantioselective induction properties. The enantioselective addition of diethylzinc to 1-naphthaldehyde and 3-chlorobenzaldehyde was achieved with an enantiomeric excess (ee) of up to 98%. All synthesized ligands were also evaluated in the addition of diethyzinc to aromatic aldehydes including an extra metal such as Ti(IV) (up to 99% ee).
Gold(I) carbenes by retro-buchner reaction: Generation and fate
Wang, Yahui,McGonigal, Paul R.,Herle, Bart,Besora, Maria,Echavarren, Antonio M.
supporting information, p. 801 - 809 (2014/02/14)
The fate of the aryl gold(I) carbenes generated by retro-Buchner reaction of ortho-substituted 7-aryl-1,3,5-cycloheptatrienes is dependent on the constitution of the ortho substituent. Indenes and fluorenes are obtained by intramolecular reaction of highly electrophilic gold(I) carbenes with alkenes and arenes. According to density functional theory calculations, the gold-catalyzed retro-Buchner process occurs stepwise, although the two carbon-carbon cleavages occur on a rather flat potential energy surface.
Group 10 metal complexes supported by pincer ligands with an olefinic backbone
Barrett, Brittany J.,Iluc, Vlad M.
, p. 2565 - 2574 (2014/06/10)
The coordination chemistry of 2,2′-bis(di-iso-propylphosphino)-trans- stilbene (tPCH-CHP) with group 10 metal centers in a variety of oxidation states is reported; different coordination modes were observed depending on the oxidation state of the metal. W
Synthesis of a guanidine NHC complex and its application in borylation reactions
Tai, Chia-Cheng,Yu, Ming-Shiuan,Chen, Yi-Lin,Chuang, Wen-Hang,Lin, Ting-Hua,Yap, Glenn P. A.,Ong, Tiow-Gan
supporting information, p. 4344 - 4346 (2014/04/17)
Synthesis of guanidine-linked NHC can be achieved easily through reacting amino-NHC with carbodiimide. Subsequently, guanidine-NHC Ag and Cu complexes were isolated and fully characterized. These Cu complexes are found to be versatile catalysts for hydroboration, semihydrogenation and carboboration of alkynes in a highly stereo- and regioselective fashion.
