17792-17-5Relevant articles and documents
STEREOCHEMICAL COURSE OF THE PALLADIUM-CATALYSED ARYLATION OF DISUBSTITUTED ACTIVATED ALKENES WITH BENZOYL CHLORIDE
Spencer, Alwyn
, p. 209 - 216 (1982)
The palladium-catalysed arylation of ten 1,1- and 1,2-disubstituted activated alkenes with benzoyl chloride was studied.In most cases, more than one product was formed.The stereochemical course of the arylation appears to be controlled by the polarity of
Synthesis and reactivity of platinum vinylcarbene complexes prepared from activation of propargyl alcohols
Ruan, Wenqing,Shi, Chuan,Sung, Herman H.Y.,Williams, Ian D.,Jia, Guochen
, p. 7 - 14 (2019)
Platinum vinylcarbene complexes are potentially useful for organometallic synthesis and catalysis, but have been rarely studied. This work reports a convenient route to make platinum vinylcarbene complexes. Treatment of [PtCl2(PPh3)]2 with propargyl alcohols HC≡CC(OH)RR’ (RR’ = Ph2, cyclo-C6H10(OH), (iPr)(C≡CTMS) and (H)(Ph)) in the presence of EtOH produced the vinylcarbene complexes trans-PtCl2{ = C(OEt)-CH=CRR’}(PPh3). Under similar condition, [PtCl2(PPh3)]2 reacted with HC≡CC(OH)Me2 to give cis-PtCl2{ = C(OEt)-CH=CMe2}(PPh3). Complex trans-PtCl2{ = C(OEt)-CH=CPh2}(PPh3) readily undergo a metathesis reaction with NaI to give trans-PtI2{ = C(OEt)-CH=CPh2}(PPh3) which can isomerize to cis-PtI2{ = C(OEt)-CH=CPh2}(PPh3). Complex trans-PtCl2{ = C(OEt)-CH=CPh2}(PPh3) reacted with PPh3 to give EtCl and the acyl complex trans-PtCl{C(O)CH=CPh2}(PPh3)2, which can undergo a decarbonylation reaction to give PtCl(CH=CPh2)(PPh3)2.
Controlling Enantioselectivity and Diastereoselectivity in Radical Cascade Cyclization for Construction of Bicyclic Structures
Lee, Wan-Chen Cindy,Mckillop, Alexander M.,Wang, Duo-Sheng,Zhang, Congzhe,Zhang, X. Peter
supporting information, p. 11130 - 11140 (2021/07/31)
Radical cascade cyclization reactions are highly attractive synthetic tools for the construction of polycyclic molecules in organic synthesis. While it has been successfully implemented in diastereoselective synthesis of natural products and other complex compounds, radical cascade cyclization faces a major challenge of controlling enantioselectivity. As the first application of metalloradical catalysis (MRC) for controlling enantioselectivity as well as diastereoselectivity in radical cascade cyclization, we herein report the development of a Co(II)-based catalytic system for asymmetric radical bicyclization of 1,6-enynes with diazo compounds. Through the fine-tuning of D2-symmetric chiral amidoporphyrins as the supporting ligands, the Co(II)-catalyzed radical cascade process, which proceeds in a single operation under mild conditions, enables asymmetric construction of multisubstituted cyclopropane-fused tetrahydrofurans bearing three contiguous stereogenic centers, including two all-carbon quaternary centers, in high yields with excellent stereoselectivities. Combined computational and experimental studies have shed light on the underlying stepwise radical mechanism for this new Co(II)-based cascade bicyclization that involves the relay of several Co-supported C-centered radical intermediates, including α-, β-, γ-, and ?-metalloalkyl radicals. The resulting enantioenriched cyclopropane-fused tetrahydrofurans that contain a trisubstituted vinyl group at the bridgehead, as showcased in several stereospecific transformations, may serve as useful intermediates for stereoselective organic synthesis. The successful demonstration of this new asymmetric radical process via Co(II)-MRC points out a potentially general approach for controlling enantioselectivity as well as diastereoselectivity in synthetically attractive radical cascade reactions.
Synthesis method of beta-chloro acid ester and alpha, beta-unsaturated acid ester compound
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Paragraph 0128-0132, (2021/08/11)
The invention belongs to the technical field of organic chemistry, and particularly relates to a synthesis method of beta-chloro acid ester and an alpha, beta-unsaturated acid ester compound. The structure of the compound is characterized by 1H NMR and 13C NMR and is confirmed. The method comprises the steps of by taking acetonitrile as a solvent, carrying out fragmentation on olefin, chlorooxalic acid monoester and 2, 6-dimethyl pyridine under a photocatalytic condition to generate an alkoxyacyl free radical intermediate, carrying out free radical addition reaction on the alkoxyacyl free radical intermediate and the olefin to generate carbon free radicals, then carrying out chlorination reaction to obtain the beta-chloro acid ester compound, and carrying out dehydrochlorination reaction under a DBU condition to generate the alpha, beta-unsaturated acid ester compound. The preparation method of the compound disclosed by the invention has the advantages of starting from olefin, being mild in condition, simple and efficient, strong in functional group compatibility and wide in substrate application range, and various beta-chloro acid ester and alpha, beta-unsaturated acid ester compounds can be synthesized from highly commercialized raw materials. On the basis of photoreaction of fluid chemistry, a target product can also be obtained with a relatively good yield, and the method has very good industrial and medicinal chemistry application values.
Recyclable and reusable PdCl2(PPh3)2/PEG-400/H2O system for the hydrophenylation of alkynes with sodium tetraphenylborate
Liu, Rong,Zhang, Tingli,Huang, Bin,Cai, Mingzhong
, p. 172 - 178 (2020/07/04)
A stable and efficient PdCl2(PPh3)2/PEG-400/H2O catalytic system for the hydrophenylation reaction of alkynes has been developed. In the presence of 3 mol% PdCl2(PPh3)2 and 2 equiv. of HOAc, the hydrophenylation of both terminal and internal alkynes with sodium tetraphenylborate proceeded smoothly in a mixture of PEG-400 and water at room temperature or 50 °C to afford a variety of phenyl-substituted alkenes in moderate to high yields. The isolation of the products was easily performed by extraction with petroleum ether, and the PdCl2(PPh3)2/PEG-400/H2O system could be readily recycled and reused six times without apparent loss of catalytic activity.