Ni-Catalyzed Decarboxylative Silylation of Alkynyl Carbonates: Access to Chiral Allenes via Enantiospecific Conversions
A Ni-mediated decarboxylative silylation of alkynyl cyclic carbonates used as versatile propargylic surrogates is reported affording a wide range of highly substituted 2,3- and 3,4-allenol products in good yields. The formal cross-coupling between a tentative intermediate Ni(allenyl) and the silyl reagent was further extended to enantiospecific conversions providing access to chiral allene synthons. This protocol marks the first Ni-catalyzed propargylic silylation proceeding through an SN2′ manifold.
Guo, Kun,Zeng, Qian,Villar-Yanez, Alba,Bo, Carles,Kleij, Arjan W.
supporting information
p. 637 - 641
(2022/01/20)
Cobalt-catalyzed hydrohydrazination of dienes and enynes: Access to allylic and propargylic hydrazides
(Chemical Equation Presented) The cobalt-catalyzed hydrohydrazination reaction of dienes and enynes is presented. Allylic and propargylic hydrazines were obtained in synthetically useful yields (allylic amines, 60-90%; propargylic amines, 47-83%) and good chemo- and regioselectivity.
Waser, Jerome,Gonzalez-Gomez, Jose C.,Nambu, Hisanori,Huber, Pascal,Carreira, Erick M.
p. 4249 - 4252
(2007/10/03)
Control of the Propargylic Radical Stabilization by Carbon-Chain Length in Manganese(III)-Mediated Reactions of 1-Alken-3-ynes. - A Facile Synthetic Way to Long-Chain 4-Acetoxy-5-alkynoic Acids
By investigation of reactions of 1-alken-3-ynes RCC-CH=CH2 4 with acetic acid/ acetic anhydride, mediated by manganese(III) acetate, it has been found that the stabilization of propargylic radical adducts depends on the carbon-chain length of R in 4.R=C8H17 is shown to be the "critical" chain length when ligand transfer reaction appears to be the only way of stabilization of intermediates, thus providing a facile one-step access to long-chain 4-acetoxy-5-alkynoic caids.The dependence of the product ratios on the AcOH/Ac2O ratio has also been demonstrated. Key Words: 1-Alken-3-ynes / Manganese(III) acetate / Propargyl radical / Ligand-transfer reaction / Electron-transfer reaction
Melikyan, Gagik G.,Mkrtchyan, Varsik M.,Badanyan, Shaliko O.,Vostrowsky, Otto,Bestmann, Hans Juergen
p. 2037 - 2040
(2007/10/02)
Konjugierte Enine durch Pyrolyse von Alkinen
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Ondruschka, Bernd,Remmler, Matthias,Zimmermann, Gerhard,Bartoszek, Michael
p. 307 - 308
(2007/10/02)
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