2441-97-6Relevant articles and documents
Copper-catalyzed hydroallylation of allenes employing hydrosilanes and allyl chlorides
Fujihara, Tetsuaki,Yokota, Ken,Terao, Jun,Tsuji, Yasushi
, p. 7898 - 7900 (2017)
The hydroallylation of allenes was developed by employing a hydrosilane and allyl chlorides in the presence of a copper catalyst. The reaction provided (E)-1,5-dienes mainly in good to high yields.
Trifluoromethylthiolation of 1, 3- and 1, 4-cyclohexadienes
Rohrbaugh,Durst,Longo,Munavalli
, p. 2639 - 2650 (2002)
Treatment of 1, 3-cyclohexadiene with CF3SCl at -80 furnishes 15 compounds. All but the two dimerized adducts arise from the free radical catalyzed addition of CF3S and Cl radicals to carbon-carbon double bonds. One dimerized product
Guanidine–Copper Complex Catalyzed Allylic Borylation for the Enantioconvergent Synthesis of Tertiary Cyclic Allylboronates
Ge, Yicen,Cui, Xi-Yang,Tan, Siu Min,Jiang, Huan,Ren, Jingyun,Lee, Nicholas,Lee, Richmond,Tan, Choon-Hong
supporting information, p. 2382 - 2386 (2019/02/01)
An enantioconvergent synthesis of chiral cyclic allylboronates from racemic allylic bromides was achieved by using a guanidine–copper catalyst. The allylboronates were obtained with high γ/α regioselectivities (up to 99:1) and enantioselectivities (up to 99 % ee), and could be further transformed into diverse functionalized allylic compounds without erosion of optical purity. Experimental and DFT mechanistic studies support an SN2′ borylation process catalyzed by a monodentate guanidine–copper(I) complex that proceeds through a special direct enantioconvergent transformation mechanism.
Mechanistic Studies on a Cu-Catalyzed Asymmetric Allylic Alkylation with Cyclic Racemic Starting Materials
Rideau, Emeline,You, Hengzhi,Sidera, Mireia,Claridge, Timothy D. W.,Fletcher, Stephen P.
supporting information, p. 5614 - 5624 (2017/04/27)
Mechanistic studies on Cu-catalyzed asymmetric additions of alkylzirconocene nucleophiles to racemic allylic halide electrophiles were conducted using a combination of isotopic labeling, NMR spectroscopy, kinetic modeling, structure-activity relationships, and new reaction development. Kinetic and dynamic NMR spectroscopic studies provided insight into the oligomeric Cu-ligand complexes, which evolve during the course of the reaction to become faster and more highly enantioselective. The Cu-counterions play a role in both selecting different pathways and in racemizing the starting material via formation of an allyl iodide intermediate. We quantify the rate of Cu-catalyzed allyl iodide isomerization and identify a series of conditions under which the formation and racemization of the allyl iodide occurs. We developed reaction conditions where racemic allylic phosphates are suitable substrates using new phosphoramidite ligand D. D also allows highly enantioselective addition to racemic seven-membered-ring allyl chlorides for the first time.1H and2H NMR spectroscopy experiments on reactions using allylic phosphates showed the importance of allyl chloride intermediates, which form either by the action of TMSCl or from an adventitious chloride source. Overall these studies support a mechanism where complex oligomeric catalysts both racemize the starting material and select one enantiomer for a highly enantioselective reaction. It is anticipated that this work will enable extension of copper-catalyzed asymmetric reactions and provide understanding on how to develop dynamic kinetic asymmetric transformations more broadly.
