62839-72-9Relevant academic research and scientific papers
Metal-Catalyzed Remote Functionalization of ω-Ene Unsaturated Ethers: Towards Functionalized Vinyl Species
Ho, Guo-Ming,Judkele, Lina,Bruffaerts, Jeffrey,Marek, Ilan
, p. 8012 - 8016 (2018/06/29)
The combined ruthenium-catalyzed chain walking with the nickel-catalyzed cross-coupling reaction of ω-alkenyl ethers provide a unique entry to functionalized vinyl species. This transformation illustrates the power and flexibility of remote functionalization by demonstrating the compatibility of two independent reactions involving unrelated sites.
Z -selective olefin synthesis via iron-catalyzed reductive coupling of alkyl halides with terminal arylalkynes
Cheung, Chi Wai,Zhurkin, Fedor E.,Hu, Xile
supporting information, p. 4932 - 4935 (2015/05/05)
Selective catalytic synthesis of Z-olefins has been challenging. Here we describe a method to produce 1,2-disubstituted olefins in high Z selectivity via reductive cross-coupling of alkyl halides with terminal arylalkynes. The method employs inexpensive and nontoxic catalyst (iron(II) bromide) and reductant (zinc). The substrate scope encompasses primary, secondary, and tertiary alkyl halides, and the reaction tolerates a large number of functional groups. The utility of the method is demonstrated in the synthesis of several pharmaceutically relevant molecules. Mechanistic study suggests that the reaction proceeds through an iron-catalyzed anti-selective carbozincation pathway.
Copper-catalyzed alkene arylation with diaryliodonium salts
Phipps, Robert J.,McMurray, Lindsay,Ritter, Stefanie,Duong, Hung A.,Gaunt, Matthew J.
supporting information; experimental part, p. 10773 - 10776 (2012/08/07)
Alkenes and arenes represent two classes of feedstock compounds whose union has fundamental importance to synthetic organic chemistry. We report a new approach to alkene arylation using diaryliodonium salts and Cu catalysis. Using a range of simple alkenes, we have shown that the product outcomes differ significantly from those commonly obtained by the Heck reaction. We have used these insights to develop a number of new tandem and cascade reactions that transform readily available alkenes into complex arylated products that may have broad applications in chemical synthesis.
Iridium as a general catalyst for the decarbonylative addition of aldehydes to alkynes
Wang, Jun,Guo, Xiangyu,Li, Chao-Jun
supporting information; experimental part, p. 211 - 215 (2011/02/17)
A general catalytic system for the decarbonylative addition reaction of aldehydes with alkynes is developed by using an iridium catalyst system. Both aromatic and aliphatic aldehydes reacted with terminal alkynes efficiently to give the corresponding olefination products in high yields and up to 11:1 E/Z selectivity.
Insertion of 1-chloro-1-lithioalkenes into organozirconocenes. A versatile synthesis of stereodefined unsaturated systems
Kasatkin, Aleksandr,Whitby, Richard J.
, p. 7039 - 7049 (2007/10/03)
Hydrozirconation of alkenes and alkynes, followed by insertion of 1- halo-1-lithio-1-alkenes, generated in situ by lithium tetramethylpiperidide deprotonation of vinyl halides, affords vinylzirconocene species which may be further elaborated. The method provides easy access to many structures including terminal (3E)- and (3Z)-1,3-dienes and (3E,5E)- and (3Z,5E)-1,3,5- trienes, and internal (E,Z)-dienes,(E,Z,E)-trienes, and (1E, 3Z)1,3-dien-5- ynes. Insertion of 2-monosubstituted 1-halo-1-lithio-1-alkenes occurs with clean inversion of configuration of the sp2-carbenoid carbon. Carbenoids derived by deprotonation of 2,2-disubstituted 1-halo-1-alkenes gave poor stereocontrol probably due to isomerization before insertion into the organozirconium species. Insertion of vinyl carbenoids into alkynylzirconocenes affords terminal (3E)- or (3Z)-1,3-dien-5-ynes, internal (1E,3Z)-1,3-dien-5-ynes, and (Z)-3-en-1,5-diynes.
A Nickel-catalyzed carbozincation of aryl-substituted alkynes
Stuedemann, Thomas,Ibrahim-Ouali, Malika,Knochel, Paul
, p. 1299 - 1316 (2007/10/03)
The addition of dialkylzincs or diphenylzinc to substituted phenylacetylenes in the presence of catalytic amounts of Ni(acac)2 in THF:NMP mixtures produces syn-carbozincation products with good to excellent regio- and stereoselectivity. After quenching with an electrophile (iodine, acyl chloride, allyl bromide) tetrasubstituted olefines are obtained in good to satisfactory yields. An intramolecular version of the reaction is possible using a terminal triple bond bearing an iodine at a remote position. More substituted iodo-alkynes furnish only reductive elimination products. An application to a stereoselective synthesis of (Z)-tamoxifen (Z:E > 99:1) has been developed.
New nickel-catalyzed carbozincation of alkynes: A short synthesis of (Z)-tamoxifen
Studemann,Knochel
, p. 93 - 95 (2007/10/03)
A new highlight in the repertoire of carbometalation reactions is the highly stereo- and regioselective nickel-catalyzed carbozincation of internal alkynes. This is exemplified by a short and effective synthesis of the anti-breast-cancer drug (Z)-tamoxifen. This reaction also allows the stereoselective synthesis of various tri- and tetrasubstituted olefins in good yield.
Synthesis of Z-alkenes from alkenylcatecholboranes through reaction with RMgX and I2 induced rearrangement
Periasamy, Mariappan,Bhanu Prasad,Suseela, Yantrapragada
, p. 2743 - 2748 (2007/10/02)
Addition of RMgX and BrMg(CH2)nMgBr reagents to alkenylcatecholborane followed by iodine induced rearrangement and oxidation provided Z-olefins and Z-olefinic alcohols in moderate to good yields. This procedure is advantageous over the previous methods of synthesis of Z-olefins from alkenylboranes since the alkyl groups which are not available through hydroborations can also be utilized.
Stereochemistry of direct olefin formation from carbonyl compounds and lithiated heterocyclic sulfones
Baudin, J. B.,Hareau, G.,Julia, S. A.,Lorne, R.,Ruel, O.
, p. 856 - 878 (2007/10/02)
The conditions for the title reaction were studied for the 2-benzothiazole and 2-pyridine series and for some examples in the 2-pyrimidine series.The olefin preparations were generally observed to be more efficient for 2-BT-sulfone systems.From the data of the hundred cases studied, it can be concluded that (E)-olefins are obtained: (i) from saturated BT-sulfones and aromatic aldehydes; and (ii) from benzylic BT-sulfones and branched saturated aldehydes (isobutyraldehyde, pivalaldehyde) or α,β-ethylenic or aromatic aldehydes. (Z)-olefins arise: (i) fom propargylic BT-sulfones and saturated or aromatic aldehydes; and (ii) from allylic or benzylic Pyr-sulfones and saturated aldehydes.Possible mechanisms for this new olefination procedure were examined. - heteroaromatic sulfones, organolithium derivatives, intramolecular ipso reactions, stereochemistry, elimination, olefination.
Alkyliron and Alkylcobalt Reagents, III. - Nonstabilized Ironalkyls: Formation, Detection, and Chemoselectivity
Kauffmann, Thomas,Laarmann, Barbara,Menges, Detlef,Neiteler, Gabriele
, p. 163 - 169 (2007/10/02)
The crystalline ate complex Me4FeLi2(Et2O)2 (1d) described in the literature as well as the complexes MeFeCl (1a), Me2Fe (1b), Me3FeLi (1c), nBu2Fe (2a), nBu4FeLi2 (2b), nOct2Fe (3a), nOct3FeLi (3b), and nOct4FeLi2 (3c) are prepared in situ by transmetallation of MeLi, nBuLi, and nOctLi with FeCl2 (readily available by in situ reduction of FeCl3 with MeLi).All these complexes have been subjected to reaction with organic substrates for the first time.Evidence for this transmetallation has been furnished by a novel test (referred to as "β-bromostyrene-ketone test").In this test, involving addition of β-bromostyrene (4) and 4-methylpentan-2-one (5), the alkyllithium compounds alkylate selectively only the ketone and the alkyliron compounds almost exclusively the β-bromostyrene.The high preference of the alkyliron reagents for the alkylation of the β-bromostyryl residue has been utilized for regioselective butylations and octylations of 1-phenyl>-ethanone (6).Moreover, in competition reactions with benzaldehydes/4-methylpentan-2-one the alkyliron reagents have been found to react usually specifically with aldehydes.The decomposition temperatures of the reagents 1a,b,c and 2b in THF have been determined to be 0, -10, 25, and -20 deg C, respectively.Key Words: Iron, organo reagents
