- Control of Vicinal Stereocenters through Nickel-Catalyzed Alkyl–Alkyl Cross-Coupling
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Vicinal stereocenters are found in many natural and unnatural compounds. Although metal-catalyzed cross-coupling reactions of unactivated alkyl electrophiles are emerging as a powerful tool in organic synthesis, there have been virtually no reports of processes that generate, much less control, vicinal stereocenters. In this investigation, we establish that a chiral nickel catalyst can mediate doubly stereoconvergent alkyl–alkyl cross-coupling, specifically, reactions of a racemic pyrrolidine-derived nucleophile with cyclic alkyl halides (as mixtures of stereoisomers) to produce vicinal stereocenters with very good stereoselectivity.
- Mu, Xin,Shibata, Yu,Makida, Yusuke,Fu, Gregory C.
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- Triphenylphosphine-Catalyzed Alkylative Iododecarboxylation with Lithium Iodide under Visible Light
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Under irradiation of 456 nm blue light-emitting diodes, PPh3 catalyzes the iododecarboxylation of aliphatic carboxylic acid derived N-(acyloxy)phthalimide with lithium iodide as an iodine source. The reaction delivers primary, secondary, and bridgehead te
- Fu, Ming-Chen,Shang, Rui,Wang, Jia-Xin
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supporting information
(2020/11/13)
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- Introduction of Cyclopropyl and Cyclobutyl Ring on Alkyl Iodides through Cobalt-Catalyzed Cross-Coupling
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A cobalt-catalyzed cross-coupling between alkyl iodides and cyclopropyl, cyclobutyl, and alkenyl Grignard reagents is disclosed. The reaction allows the introduction of strained rings on a large panel of primary and secondary alkyl iodides. The catalytic system is simple and nonexpensive, and the reaction is general, chemoselective, and diastereoconvergent. The alkene resulting from the cross-coupling can be transformed to substituted cyclopropanes using a Simmons-Smith reaction. The formation of radical intermediates during the coupling is hypothesized.
- Andersen, Claire,Ferey, Vincent,Daumas, Marc,Bernardelli, Patrick,Guérinot, Amandine,Cossy, Janine
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p. 2285 - 2289
(2019/03/29)
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- Mild and phosphine-free iron-catalyzed cross-coupling of nonactivated secondary alkyl halides with alkynyl grignard reagents
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A simple protocol for iron-catalyzed cross-coupling of nonactivated secondary alkyl bromides and iodides with alkynyl Grignard reagents at room temperature has been developed. A wide range of secondary alkyl halides and terminal alkynes are tolerated to a
- Cheung, Chi Wai,Ren, Peng,Hu, Xile
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supporting information
p. 2566 - 2569
(2014/05/20)
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- Preparation of stereodefined secondary alkyllithium compounds
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We have developed a practical stereoretentive iodine/lithium-exchange process that allows the stereodefined preparation of cis- and trans-cycloalkyllithium compounds from their corresponding stereodefined iodides. Quenching with electrophiles offers stere
- Seel, Stephanie,Dagousset, Guillaume,Thaler, Tobias,Frischmuth, Annette,Karaghiosoff, Konstantin,Zipse, Hendrik,Knochel, Paul
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supporting information
p. 4614 - 4622
(2013/05/08)
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- Enantioselective preparation of 4-substituted cyclohexenes by radical fragmentation of sulfoxides
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(equation presented) Radical fragmentation of o-bromophenyl sulfoxides is reported. Starting from enantiomerically pure material, 4-substituted cyclohexene derivatives have been prepared with enantiomeric excesses between 70% and 86%. The key step of the process is a diastereoselective abstraction of a hydrogen atom by the initial aryl radical. The highest enantiomeric exesses have been obtained in the presence of aluminum Lewis acids.
- Imboden, Christoph,Villar, Felix,Renaud, Philippe
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p. 873 - 875
(2008/02/09)
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- Preparation and reactivity of chiral β-amino-alkylzinc iodides and related configurationally stable zinc organometallics
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Several zinc organometallics bearing at the β-position a carbamate or an amido function with an acidic N-H group were prepared using the direct insertion of zinc dust into the corresponding alkyl iodides in THF or THF:DMSO mixtures. Most of the starting iodides were obtained from natural α-amino acids and the resulting zinc species afforded after transmetalation with CuCN.2LiCl and reaction with a selection of relatively reactive electrophiles a variety of polyfunctional 1,2-amino alcohol derivatives and carbamates in optically pure form. Several secondary β-amido alkyl iodides were converted to the corresponding chiral zinc reagents and trapped with electrophiles. The configurational stability of chiral secondary organozinc compounds and the stereochemical course of their reactions were examined.
- Duddu,Eckhardt,Furlong,Knoess,Berger,Knochel
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p. 2415 - 2432
(2007/10/02)
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