7697-55-4Relevant academic research and scientific papers
Copper-Catalyzed Enantiotopic-Group-Selective Allylation of gem-Diborylalkanes
Kim, Minjae,Park, Bohyun,Shin, Minkyeong,Kim, Suyeon,Kim, Junghoon,Baik, Mu-Hyun,Cho, Seung Hwan
supporting information, p. 1069 - 1077 (2021/01/25)
We report a copper-catalyzed enatiotopic-group-selective allylation of gem-diborylalkanes with allyl bromides. The combination of copper(I) bromide and H8-BINOL derived phosphoramidite ligand proved to be the most effective catalytic system to provide various enantioenriched homoallylic boronate esters, containing a boron-substituted stereogenic center that is solely derived from gem-diborylalkanes, in good yields with high enantiomeric ratios under mild conditions. Experimental and theoretical studies have been conducted to elucidate the reaction mechanism, revealing how the enatiotopic-group-selective transmetalation of gem-diborylalkanes with chiral copper complex occurs to generate chiral α-borylalkyl-copper species for the first time. Additional synthetic applications to the synthesis of various chiral building blocks are also included.
Asymmetric Reductive and Alkynylative Heck Bicyclization of Enynes to Access Conformationally Restricted Aza[3.1.0]bicycles
Chi, Yonggui Robin,Huang, Xiaolei,Nguyen, Minh Hieu,Pu, Maoping,Wu, Yun-Dong,Zhang, Luoqiang,Zhou, Jianrong Steve
supporting information, p. 10814 - 10818 (2020/06/09)
Conformationally restricted azabicycles are becoming increasingly important in medicinal research. Asymmetric Heck bicyclization of enynes proceeds to give medicinally useful aza[3.1.0] and aza[4.1.0] bicycles with excellent enantioselectivity. The key organopalladium species after bicyclization can be trapped by silanes and terminal alkynes.
Intramolecular Remote C-H Activation via Sequential 1,4-Palladium Migration to Access Fused Polycycles
Li, Panpan,Li, Qiuyu,Weng, He,Diao, Jiaming,Yao, Hequan,Lin, Aijun
supporting information, p. 6765 - 6769 (2019/09/07)
An unprecedented intramolecular remote C-H activation via sequential 1,4-palladium migration with an aromatic ring as a conveyor has been described. This reaction provides an efficient route to construct diverse polycyclic frameworks in moderate to good yield via palladium-catalyzed remote C-H activation/alkene insertion, arylation, alkenylation, and the Heck reaction. The preliminary mechanistic studies revealed that the 1,4-palladium migration process was reversible.
Synthesis of Chiral Tertiary Boronic Esters by Oxime-Directed Catalytic Asymmetric Hydroboration
Shoba, Veronika M.,Thacker, Nathan C.,Bochat, Andrew J.,Takacs, James M.
supporting information, p. 1465 - 1469 (2016/02/12)
Chiral boronic esters are useful intermediates in asymmetric synthesis. We have previously shown that carbonyl-directed catalytic asymmetric hydroboration (CAHB) is an efficient approach to the synthesis of functionalized primary and secondary chiral boronic esters. We now report that the oxime-directed CAHB of alkyl-substituted methylidene and trisubstituted alkene substrates by pinacolborane (pinBH) affords oxime-containing chiral tertiary boronic esters with yields up to 87 % and enantiomeric ratios up to 96:4 e.r. The utility of the method is demonstrated by the formation of chiral diols and O-substituted hydroxylamines, the generation of quaternary carbon stereocenters through carbon-carbon coupling reactions, and the preparation of chiral 3,4,4-trisubstituted isoxazolines.
Enantioselective bromocyclization of allylic amides catalyzed by BINAP derivatives
Kawato, Yuji,Kubota, Akino,Ono, Hiromi,Egami, Hiromichi,Hamashima, Yoshitaka
supporting information, p. 1244 - 1247 (2015/03/14)
A highly enantioselective bromocyclization of allylic amides with N-bromosuccinimide (NBS) was developed with DTBM-BINAP as a catalyst, affording chiral oxazolines with a tetrasubstituted carbon center in high yield with up to 99% ee. By utilizing the bro
Catalytic, enantioselective, and highly chemoselective bromocyclization of olefinic dicarbonyl compounds
Zhao, Yi,Jiang, Xiaojian,Yeung, Ying-Yeung
, p. 8597 - 8601 (2013/09/12)
Overriding preferences: An amine-thiocarbamate catalyst can mediate the facile, efficient, and highly enantioselective bromocyclization of olefinic 1,3-dicarbonyl compounds. In the presence of the bifunctional catalyst, the bromination occurs chemoselectively at the olefinic moiety rather than at the carbon atom in the α-position to the carbonyl units. Copyright
Construction of enantioenriched cyclic compounds by asymmetric allylic alkylation and ring-closing metathesis
Giacomina, Francesca,Alexakis, Alexandre
supporting information, p. 6710 - 6721 (2013/11/06)
A new approach to highly enantioenriched cyclic compounds (up to 98a€‰% ee) has been developed by using ω-ethylenic allylic substrates in a one-pot asymmetric allylic alkylation and ring-closing metathesis sequence. The starting compounds are synthetic equivalents of cyclic allylic substrates. The method is exemplified with both Cu and Ir catalysts, and chiral phosphoramidite ligands. A new approach to highly enantioenriched cyclic compounds (up to 98a€‰% ee) has been developed by using ω-ethylenic allylic substrates in a one-pot asymmetric allylic alkylation and ring-closing metathesis sequence. The starting compounds are synthetic equivalents of cyclic allylic substrates. The method is exemplified with both Cu and Ir catalysts, and chiral phosphoramidite ligands. Copyright
γ-Selective directed catalytic asymmetric hydroboration of 1,1-disubstituted alkenes
Smith, Sean M.,Hoang, Gia L.,Pal, Rhitankar,Khaled, Mohammad O. Bani,Pelter, Liberty S. W.,Zeng, Xiao Cheng,Takacs, James M.
supporting information, p. 12180 - 12182 (2013/01/16)
Directed catalytic asymmetric hydroborations of 1,1-disubstituted alkenes afford γ-dioxaborato amides and esters in high enantiomeric purity (90-95% ee). The Royal Society of Chemistry 2012..
Anti-inflammatory furanone compounds
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, (2008/06/13)
New furanone compounds have anti-inflammatory, immunosuppresive and anti-proliferative activity and are useful in treating psoriasis and modifying calcium homeostasis. A compound of the invention is 4-[3,6-dihydro-6-hydroxy-5-(3-phenylpropyl)-2H-pyran-2-y
Facile One-pot Transformation of Carboxylic Acid Chlorides into 2-Substituted Allyl Alcohols or Epichlorohydrins
Barluenga, Jose,Fernandez-Simon, Jose L.,Concellon, Jose M.,Yus, Miguel
, p. 77 - 80 (2007/10/02)
Treatment of carboxylic acid chlorides (1) with chloromethyl-lithium generated in-situ (1:2 molar ratio) in the presence of lithium iodide leads, after hydrolysis, to the corresponding homologated 2-substituted allyl alcohols (2).When the same reaction is carried out using iodide-free butyl-lithium, instead of methyl-lithium-lithium iodide, the corresponding 2-substituted epichlorohydrines (5) are formed.
