60155-90-0Relevant academic research and scientific papers
Regio- and Stereoselective Diarylation of 1,3-Dienes via Ni/Cr Cocatalysis
Chen, Qing-An,Hu, Yan-Cheng,Ji, Ding-Wei,Li, Ying,Zhang, Wei-Song,Zhang, Xiang-Xin,Zhao, Chao-Yang
, p. 2158 - 2165 (2022/02/14)
Through the formation of the thermodynamically favored Cr(III)-O bond, the Nozaki-Hiyama-Kishi reaction has been widely applied in the functionalization of carbonyl compounds with the help of Ni catalysis. Herein, a divergent regio- and stereoselective diarylation of dienes has been developed under Ni/Cr cocatalysis without the inherent driving force for the formation of polar metal alkoxides. Preliminary experimental studies have been conducted to elucidate the key roles of Ni, Cr, and redox-active bis(imino)pyridine (PDI) ligands. The proposed mechanism suggests that the newly formed C-C bond of this diarylation was created by organonickel species instead of organochromium species.
Friedel-Crafts Reactions of Some Conjugated Epoxides
Taylor, Stephen K.,Clark, Daniel L.,Heinz, Karl L.,Schramm, Scott B.,Westermann, Cindy D.,Barnell, Koleen K.
, p. 592 - 596 (2007/10/02)
The Friedel-Crafts (FC) reactions of (1,2-epoxyethyl)benzene, 1,2-epoxy-1-p-tolylethane, 1,2-epoxy-1-(p-methoxyphenyl)ethane, 1,2-epoxy-3-butene, and 1,2-epoxy-2-methyl-3-butene were examined under various conditions.Reaction time, temperature, Lewis acid, Lewis acid concentration, and solvent were varied.For (1,2-epoxyethyl)benzene (1), aromatic nucleophilicity was shown to be an important factor in promoting good FC yields.It was also shown that para carbocation stabilizing substituents on 1 did not improve FC yields.Vinyloxirane yielded primary products from direct ring opening (2-aryl-3-buten-1-ols) and conjugate addition (4-aryl-2-buten-1-ols) and secondary products (1,4-diaryl-2-butenes).Increased reaction time or catalyst concentration increases the proportion of secondary products.The primary and secondary FC pathways gave an excellent opportunity for study of the effects on product distributions of the use of aluminum chloride, boron trifluoride etherate, and stannic chloride Lewis acids.A significant FC reaction yield was not obtained with 1,2-epoxy-2-methyl-3-butene and toluene under the same conditions used for 1,2-eopoxy-3-butene.Presumably this results from steric effects.All products can be explained by attack of the aromatic nucleophile on the epoxide position (or positions) most capable of stabilizing incipient positive character.The epoxide is also less electrophilic than other alkylating agents under similar conditions.An explanation for this is given.
