- Selective Hydroarylation of 1,3-Diynes Using a Dimeric Manganese Catalyst: Modular Synthesis of Z-Enynes
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The transition-metal-catalyzed selective hydroarylation of unsymmetrical alkynes represents the state-of-art in organic chemistry, and still mainly relies on the use of precious late-transition-metal catalysts. Reported herein is an unprecedented MnI-catalyzed hydroarylation of unsymmetrical 1,3-diyne alcohols with commercially available arylboronic acids with predictive selectivity. This method addresses the challenges in regio-, stereo-, and chemoselectivity. It offers a general, convenient and practical strategy for the modular synthesis of multisubstituted Z-configurated conjugated enynes. This protocol is distinguished by its operational simplicity, complete selectivity, excellent functional-group compatibility, and gram-scale potential. A dimeric MnI species, Mn2(CO)8Br2, was proven to be a much more efficient catalyst precursor than Mn(CO)5Br.
- Yan, Zhongfei,Yuan, Xiang-Ai,Zhao, Yue,Zhu, Chengjian,Xie, Jin
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supporting information
p. 12906 - 12910
(2018/09/25)
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- Nickel-catalyzed oxidative coupling reactions of two different terminal alkynes using O2 as the oxidant at room temperature: Facile syntheses of unsymmetric 1,3-diynes
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(Formula Presented) Two different terminal alkynes now can be coupled together in the presence of NiCl2-6H2O/Cul by using an excess of one of the terminal alkyne substrates. The new method employed 20 mol % TMEDA as the ligand and environmentally benign O2 or air as the oxidant. It is the first example using Ni-salt as catalyst by employing air or O2 as oxidant, which led to efficient heterocoupling of two different alkynes.
- Yin, Weiyan,He, Chuan,Chen, Mao,Zhang, Heng,Lei, Aiwen
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scheme or table
p. 709 - 712
(2009/08/12)
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