37438-00-9Relevant academic research and scientific papers
Enantioselective Hydroazidation of Trisubstituted Non-Activated Alkenes
Meyer, Daniel,Renaud, Philippe
, p. 10858 - 10861 (2017/08/30)
A one-pot procedure for the enantioselective hydroazidation of non-activated trisubstituted alkenes is described. Hydroboration with monoisopinocampheylborane (IpcBH2) provides dialkylboranes that are in situ selectively converted into monoalkyl-substituted catecholboranes; these undergo radical azidation upon treatment with benzenesulfonyl azide and a radical initiator. Enantiomerically enriched azides were thus obtained in yields of 59–81 % and enantioselectivities of up to 94:6 e.r. (98:2 e.r. if the intermediate dialkylborane is purified by crystallization). A rapid access to enantiomerically pure (+)-rodocaine is also described. The use of other arenesulfonyl radical traps enables enantioselective hydroallylation, hydrosulfanylation, and hydrobromination reactions with yields of 71–86 %.
A highly active and general catalyst for the stille coupling reaction of unreactive aryl, heteroaryl, and vinyl chlorides under mild conditions
Lee, Dong-Hwan,Qian, Yingjie,Park, Ji-Hoon,Lee, Jong-Suk,Shim, Sang-Eun,Jin, Myung-Jong
supporting information, p. 1729 - 1735 (2013/07/19)
A β-diketiminatophosphane-palladium complex was found to act as an efficient and general catalyst in the Stille coupling reaction of various aryl and heteroaryl chlorides with organostannanes. The results show that this catalytic system allows for the use of less reactive substrates such as deactivated or sterically hindered aryl chlorides. A catalyst loading of 0.5 mol% was sufficient to achieve excellent performance under relatively mild reaction conditions. Furthermore, the scope of catalyst was extended to the coupling of vinyl chlorides. Copyright
Achieving vinylic selectivity in Mizoroki-heck reaction of cyclic olefins
Wu, Xiaojin,Lu, Yunpeng,Hirao, Hajime,Zhou, Jianrong
supporting information, p. 6014 - 6020 (2013/06/26)
In Heck reactions of cyclic olefins, the products usually have aryl groups that end up at the allylic and/or homoallylic position. We herein report new selectivity that adds aryl groups to the vinylic position. Cyclic olefins of various ring size worked well. The desired isomers were produced by palladium-hydride-catalyzed isomerization of the initial products. Thus, a specific catalyst must be used so that it can perform two jobs under one set of reaction conditions. Copyright
Tetra-ortho-substituted biaryls through palladium-catalyzed suzuki miyaura couplings with a diaminochlorophosphine ligand
Ackermann, Lutz,Potukuchi, Harish K.,Althammer, Andreas,Born, Robert,Mayer, Peter
supporting information; experimental part, p. 1004 - 1007 (2010/06/16)
Chemical Equetion Presentation A palladium complex derived from a sterically hindered diaminochlorophosphine allowed for Suzuki-Miyaura cross-couplings of chloroarenes with ample scope and provided access to tetra-ortho-substituted bi(hetero)aryls.
A ligand free and room temperature protocol for Pd-catalyzed kumada-corriu couplings of unactivated alkenyl phosphates
Gauthier, Delphine,Beckendorf, Stephan,Gogsig, Thomas M.,Lindhardt, Anders T.,Skrydstrup, Troels
supporting information; experimental part, p. 3536 - 3539 (2009/09/30)
Kumada - Corriu cross-couplings of nonactivated cyclic and acyclic vinyl phosphates with aryl magnesium reagents afforded a series of 1,1-disubtituted alkenes in good yields for most cases when the reactions were performed at room temperature with the sim
Arenediazonium o-benzenedisulfonimides as efficient reagents for Heck-type arylation reactions
Artuso, Emma,Barbero, Margherita,Degani, Iacopo,Dughera, Stefano,Fochi, Rita
, p. 3146 - 3157 (2007/10/03)
Arenediazonium o-benzenedisulfonimides can be used as new and efficient reagents for Heck-type arylation reactions of some common substrates containing C-C multiple bonds, namely ethyl acrylate, acrylic acid, acroleyne, styrene and cyclopentene. The reactions were carried out in an organic solvent, in the presence of Pd(OAc)2 as pre-catalyst, and gave rise to arylated products, for example, ethyl cinnamates, cinnamic acids, cinnamic aldehydes and stilbenes, possessing an (E)-configuration, and 1-arylcyclopentenes, in good to excellent yields. It is noteworthy that all the reactions led to the recovery, in greater than 80% yield, of o-benzenedisulfonimide, recyclable for the preparation of other diazonium salts.
Pd/P(t-Bu)3: A mild and general catalyst for stille reactions of aryl chlorides and aryl bromides
Littke, Adam F.,Schwarz, Lothar,Fu, Gregory C.
, p. 6343 - 6348 (2007/10/03)
Pd/P(t-Bu)3 serves as an unusually reactive catalyst for Stille reactions of aryl chlorides and bromides, providing solutions to a number of long-standing challenges. An unprecedented array of aryl chlorides can be cross-coupled with a range of organotin reagents, including SnBu4. Very hindered biaryls (e.g., tetra-ortho-substituted) can be synthesized, and aryl chlorides can be coupled in the presence of aryl triflates. The method is user-friendly, since a commercially available complex, Pd(P(t-Bu)3)2, is effective. Pd/P(t-Bu)3 also functions as an active catalyst for Stille reactions of aryl bromides, furnishing the first general method for room-temperature cross-couplings.
Versatile catalysts for the Suzuki cross-coupling of arylboronic acids with aryl and vinyl halides and triflates under mild conditions
Littke, Adam F.,Dai, Chaoyang,Fu, Gregory C.
, p. 4020 - 4028 (2007/10/03)
Through the use of Pd2(dba)3/P(t-Bu)3 as a catalyst, a wide range of aryl and vinyl halides, including chlorides, undergo Suzuki cross-coupling with arylboronic acids in very good yield, typically at room temperature; through use of Pd(OAc)2/PCy3, a diverse array of aryl and vinyl triflates react cleanly at room temperature. Together, these two catalyst systems cover a broad spectrum of commonly encountered substrates for Suzuki couplings. Furthermore, they display novel reactivity patterns, such as the selective cross-coupling by Pd2(dba)3/P(t-Bu)3 of an aryl chloride in preference to an aryl triflate, and they can be used at low loading, even for reactions of aryl chlorides. Preliminary mechanistic work indicates that a palladium monophosphine complex is the active catalyst in the cross-coupling of aryl halides.
