77208-20-9Relevant academic research and scientific papers
Zirconium-Catalyzed Synthesis of Alkenylaminoboranes: From a Reliable Preparation of Alkenylboronates to a Direct Stereodivergent Access to Alkenyl Bromides
Birepinte, Mélodie,Chabaud, Laurent,Liautard, Virginie,Pucheault, Mathieu
supporting information, p. 2838 - 2843 (2020/04/16)
A simple procedure has been optimized for the preparation of alkenylaminoborane from alkynes using diisopropylaminoborane and HZrCp2Cl. Coupled with a magnesium-catalyzed dehydrogenation, it allowed for the use of air- and moisture-stable diisopropylamine. This synthesis has been extended to a one-pot sequence leading directly to bromoalkenes with controlled stereochemistry. As such, it provides an easy, scalable, cheap process to access alkenylboronates and both (E)- and (Z)-bromoalkenes from commercially available alkynes.
Remote Nucleophilic Allylation by Allylrhodium Chain Walking
Groves, Alistair,Martínez, Jose I.,Smith, Joshua J.,Lam, Hon Wai
supporting information, p. 13432 - 13436 (2018/09/21)
Metal migration through a carbon chain is a versatile method for achieving remote functionalization. However, almost all known examples involve the overall net migration of alkylmetal species. Here, we report that allylrhodium species obtained from hydrorhodation of 1,3-dienes undergo chain walking toward esters, amides, or (hetero)arenes over distances of up to eight methylene units. The final, more highly conjugated allylrhodium species undergo nucleophilic allylation with aldehydes and with an imine to give Z-homoallylic alcohols and amines, respectively.
Stereodivergent Olefination of Enantioenriched Boronic Esters
Armstrong, Roly J.,García-Ruiz, Cristina,Myers, Eddie L.,Aggarwal, Varinder K.
supporting information, p. 786 - 790 (2017/01/14)
A stereodivergent coupling reaction between vinyl halides and boronic esters is described. This coupling process proceeds without a transition-metal catalyst, instead proceeding by electrophilic selenation or iodination of a vinyl boronate complex followed by stereospecific syn or anti elimination. Chiral, nonracemic boronic esters could be coupled with complete enantiospecificity. The process enables the highly stereoselective synthesis of either the E or Z alkene from a single isomer of a vinyl coupling partner.
Nickel-Catalyzed Reductive Cross-Coupling of Vinyl Bromides with Unactivated Alkyl Halides
Gu, Jun,Qiu, Canbin,Lu, Wenbin,Qian, Qun,Lin, Kunhua,Gong, Hegui
supporting information, p. 1867 - 1873 (2017/04/06)
The use of pyridine as the sole ligand for the reductive vinylation of unactivated secondary alkyl halides under Ni-catalyzed conditions has been developed. Both alkyl- and aryl-substituted vinyl bromides are suitable, in which alkyl-decorated α-alkenyl bromides resulted in the α-products in good results.
Preparation of Vinyl Arenes by Nickel-Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides
Liu, Jiandong,Ren, Qinghua,Zhang, Xinghua,Gong, Hegui
, p. 15544 - 15548 (2016/12/09)
This work emphasizes the synthesis of substituted vinyl arenes by reductive coupling of aryl halides with vinyl bromides under mild and easy-to-operate nickel-catalyzed reaction conditions. A broad range of aryl halides, including heteroaromatics, and vinyl bromides were employed to yielding products in moderate to excellent yields with high functional-group tolerance. The nickel-catalytic system displays good chemoselectivity between the two C(sp2)-halide coupling partners, thus demonstrating a mechanistic pathway distinct from other stepwise protocols.
Ni-catalyzed reductive coupling of α-halocarbonyl derivatives with vinyl bromides
Qiu, Canbin,Yao, Ken,Zhang, Xinghua,Gong, Hegui
supporting information, p. 11332 - 11335 (2016/12/18)
This work describes the vinylation of α-halo carbonyl compounds with vinyl bromides under Ni-catalyzed reductive coupling conditions. While aryl-conjugated vinyl bromides entail pyridine as the sole labile ligand, the alkyl-substituted vinyl bromides require both bipyridine and pyridine as the co-ligands.
A new entry of highly nucleophilic CHBr3-TiCl4-Mg system for the stereoselective synthesis of 1-alkenyl bromides
Bhorge, Yeshwant Ramchandra,Chang, Su-Haur,Chang, Cheng-Ta,Yan, Tu-Hsin
experimental part, p. 4846 - 4851 (2012/08/07)
This TiCl4-Mg promoted coupling of CHBr3 with various aldehydes and ketones, especially in sterically hindered or enolizable ketones, provides a simple, practical, and stereoselective carbonyl-bromomethylenation leading primarily to (E)-vinyl bromides.
TBAF-promoted dehydrobrominations of vicinal dibromides having an adjacent O-functional group
Kutsumura, Noriki,Kubokawa, Keisuke,Saito, Takao
experimental part, p. 2717 - 2720 (2010/12/25)
Regioselective HBr elimination of vicinal dibromides having an adjacent oxygen functional group to give the corresponding 2-bromoalk-1-enes was controlled using 1.1 equivalents of TBAF. Two-step elimination to give the corresponding alkynes was controlled using 5.0 equivalents of TBAF. High yield and high selectivity require the presence of an oxygen functional group at the neighboring position of the elimination site.
Palladium-catalyzed carbene insertion into vinyl halides and trapping with amines
Devine, Sean K. J.,Van Vranken, David L.
, p. 2047 - 2049 (2008/02/02)
Palladium is shown to catalyze the three-component coupling of vinyl halides, trimethytsilyldiazomethane, and amines to generate allylamines. The mechanism is believed to Involve formation of an R-Pd=CHSiMe3 intermediate that undergoes migratio
A new and facile method for stereoselective synthesis of (E)-styryl bromides by the reduction of 1,1-dibromoalkenes using LiAlH4-EtOAc (1:1)
Horibe, Hideo,Kondo, Kazuhiro,Okuno, Hiroaki,Aoyama, Toyohiko
, p. 986 - 988 (2007/10/03)
A facile method for stereoselective synthesis of (E)-styryl bromides by the reduction of 1,1-dibromoalkenes using LiAlH4-EtOAc (1:1) is described. We believe that the present procedure is a good alternative to the Tokuda's microwave method with good stereoselectivity.
