137364-99-9Relevant articles and documents
Regio- and stereoselective synthesis of bromoalkenes by homolytic hydrobromination of alkynes with hydrogen bromide
Kinoshita, Hidenori,Kumaki, Wataru,Miura, Katsukiyo
, (2022/03/07)
Homolytic hydrobromination of terminal and internal alkynes with a commercially available solution of hydrogen bromide in acetic acid has been investigated for regio- and stereoselective synthesis of bromoalkenes. Under an aerobic atmosphere at room temperature, the reaction of ethynylarenes with a small excess of HBr efficiently gave (2-bromoethenyl)arenes with good to high E-selectivity. (Alk-1-ynyl)arenes, or internal alkynes bearing both phenyl and alkyl groups at the sp-carbons also underwent the air-initiated hydrobromination to exhibit high Z-selectivity under kinetic conditions using a half equivalent of HBr.
Alkyliron and Alkylcobalt Reagents, III. - Nonstabilized Ironalkyls: Formation, Detection, and Chemoselectivity
Kauffmann, Thomas,Laarmann, Barbara,Menges, Detlef,Neiteler, Gabriele
, p. 163 - 169 (2007/10/02)
The crystalline ate complex Me4FeLi2(Et2O)2 (1d) described in the literature as well as the complexes MeFeCl (1a), Me2Fe (1b), Me3FeLi (1c), nBu2Fe (2a), nBu4FeLi2 (2b), nOct2Fe (3a), nOct3FeLi (3b), and nOct4FeLi2 (3c) are prepared in situ by transmetallation of MeLi, nBuLi, and nOctLi with FeCl2 (readily available by in situ reduction of FeCl3 with MeLi).All these complexes have been subjected to reaction with organic substrates for the first time.Evidence for this transmetallation has been furnished by a novel test (referred to as "β-bromostyrene-ketone test").In this test, involving addition of β-bromostyrene (4) and 4-methylpentan-2-one (5), the alkyllithium compounds alkylate selectively only the ketone and the alkyliron compounds almost exclusively the β-bromostyrene.The high preference of the alkyliron reagents for the alkylation of the β-bromostyryl residue has been utilized for regioselective butylations and octylations of 1-phenyl>-ethanone (6).Moreover, in competition reactions with benzaldehydes/4-methylpentan-2-one the alkyliron reagents have been found to react usually specifically with aldehydes.The decomposition temperatures of the reagents 1a,b,c and 2b in THF have been determined to be 0, -10, 25, and -20 deg C, respectively.Key Words: Iron, organo reagents
