229184-98-9Relevant academic research and scientific papers
Cu-catalyzed enantioselective alkylarylation of vinylarenes enabled by chiral binaphthyl-box hybrid ligands
Sakurai, Shunya,Matsumoto, Akira,Kano, Taichi,Maruoka, Keiji
, p. 19017 - 19022 (2020/11/02)
Transition-metal-catalyzed radical relay coupling reactions have recently emerged as one of the most powerful methods to achieve difunctionalization of olefins. However, there has been limited success in applying this method to asymmetric catalysis using an effective chiral ligand. Herein we report the Cu-catalyzed enantioselective alkylarylation of vinylarenes using alkylsilyl peroxides as alkyl radical sources. This reaction proceeds under practical reaction conditions and affords chiral 1,1-diarylalkane structures that are found in a variety of bioactive molecules. Notably, a highly enantioselective reaction was accomplished by combining chiral bis(oxazoline) ligands with chiral binaphthyl scaffolds.
Catalytic Asymmetric Fluorination of Copper Carbene Complexes: Preparative Advances and a Mechanistic Rationale
Buchsteiner, Michael,Fürstner, Alois,Jerabek, Paul,Lehmann, Christian W.,Martinez-Rodriguez, Luis,N?thling, Nils,Patzer, Michael,Pozo, Iago
supporting information, p. 2509 - 2515 (2020/02/26)
The Cu-catalyzed reaction of substituted α-diazoesters with fluoride gives α-fluoroesters with ee values of up to 95 %, provided that chiral indane-derived bis(oxazoline) ligands are used that carry bulky benzyl substituents at the bridge and moderately bulky isopropyl groups on their core. The apparently homogeneous solution of CsF in C6F6/hexafluoroisopropanol (HFIP) is the best reaction medium, but CsF in the biphasic mixture CH2Cl2/HFIP also provides good results. DFT studies suggest that fluoride initially attacks the Cu- rather than the C-atom of the transient donor/acceptor carbene intermediate. This unusual step is followed by 1,2-fluoride shift; for this migratory insertion to occur, the carbene must rotate about the Cu?C bond to ensure orbital overlap. The directionality of this rotatory movement within the C2-symmetric binding site determines the sense of induction. This model is in excellent accord with the absolute configuration of the resulting product as determined by X-ray diffraction using single crystals of this a priori wax-like material grown by capillary crystallization.
Ethynylbenziodazolones (EBZ) as Electrophilic Alkynylation Reagents for the Highly Enantioselective Copper-Catalyzed Oxyalkynylation of Diazo Compounds
Hari, Durga Prasad,Schouwey, Lionel,Barber, Verity,Scopelliti, Rosario,Fadaei-Tirani, Farzaneh,Waser, Jerome
supporting information, (2019/05/28)
Ethynylbenziodoxol(on)e (EBX) cyclic hypervalent iodine reagents are now established reagents for the alkynylation of radicals and nucleophiles, yet they present limited possibilities for further structure and reactivity modification. Herein, the first synthesis is reported for the corresponding ethynylbenziodazolone (EBZ) reagents, in which the oxygen atom in the iodoheterocycle is replaced by a nitrogen atom. The substituent on the nitrogen enables further fine-tuning of the reagent structure and reactivity. EBZ reagents are obtained easily from the corresponding benzamides by using a one-step procedure, and display reactivity comparable to that of EBX reagents. In particular, they are applied in an asymmetric copper-catalyzed oxyalkynylation of diazo compounds, which proceeds in high yield and enantioselectivity for a broad range of substituents on the diazo compounds and the alkyne.
Synthesis of Enantioenriched Allylic Silanes via Nickel-Catalyzed Reductive Cross-Coupling
Hofstra, Julie L.,Cherney, Alan H.,Ordner, Ciara M.,Reisman, Sarah E.
, p. 139 - 142 (2018/01/17)
An asymmetric Ni-catalyzed reductive cross-coupling has been developed to prepare enantioenriched allylic silanes. This enantioselective reductive alkenylation proceeds under mild conditions and exhibits good functional group tolerance. The chiral allylic silanes prepared here undergo a variety of stereospecific transformations, including intramolecular Hosomi-Sakurai reactions, to set vicinal stereogenic centers with excellent transfer of chirality.
Nickel-Catalyzed Enantioselective Cross-Coupling of N-Hydroxyphthalimide Esters with Vinyl Bromides
Suzuki, Naoyuki,Hofstra, Julie L.,Poremba, Kelsey E.,Reisman, Sarah E.
, p. 2150 - 2153 (2017/04/27)
An enantioselective Ni-catalyzed cross-coupling of N-hydroxyphthalimide esters with vinyl bromides is reported. The reaction proceeds under mild conditions and uses tetrakis(N,N-dimethylamino)ethylene as a terminal organic reductant. Good functional group tolerance is demonstrated, with over 20 examples of reactions that proceed with >90% ee.
Enantioselective Copper-Catalyzed Oxy-Alkynylation of Diazo Compounds
Hari, Durga Prasad,Waser, Jerome
supporting information, p. 8420 - 8423 (2017/07/06)
Enantioselective catalytic methods allowing the addition of both a nucleophile and an electrophile onto diazo compounds give a fast access into important building blocks. Herein, we report the highly enantioselective oxyalkynylation of diazo compounds usi
Nickel-catalyzed asymmetric reductive cross-coupling between vinyl and benzyl electrophiles
Cherney, Alan H.,Reisman, Sarah E.
supporting information, p. 14365 - 14368 (2014/12/11)
A Ni-catalyzed asymmetric reductive cross-coupling between vinyl bromides and benzyl chlorides has been developed. This method provides direct access to enantioenriched products bearing aryl-substituted tertiary allylic stereogenic centers from simple, stable starting materials. A broad substrate scope is achieved under mild reaction conditions that preclude the pregeneration of organometallic reagents and the regioselectivity issues commonly associated with asymmetric allylic arylation.
METHOD OF PREPARING A RING COMPOUND HAVING TWO ADJACENT CHIRAL CENTERS
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Page 39-40, (2010/02/09)
A method of synthesizing a chiral compound having a quarternary carbon atom bearing diastereotopic groups from (a) a nitroolefin and (b) an α-substituted β-dicarbonyl or an equivalent compound having an acidic C-H moiety compound is disclosed. A subsequen
Development of a catalytic enantioselective conjugate addition of 1,3-dicarbonyl compounds to nitroalkenes for the synthesis of endothelin-A antagonist ABT-546. Scope, mechanism, and further application to the synthesis of the antidepressant rolipram
Barnes, David M.,Wittenberger, Steven J.,Zhang, Ji,Ji, Jianguo,Fickes, Michael G.,Fitzgerald, Michael A.,King, Steven A.,Morton, Howard E.,Plagge, Frederick A.,Preskill, Margo,Wagaw, Seble H.
, p. 13097 - 13105 (2007/10/03)
The enantioselective synthesis of endothelin-A antagonist ABT-546 has been accomplished via the discovery and development of a highly selective catalytic asymmetric conjugate addition of ketoesters to nitroolefins. Employing just 4 mol % bis(oxazoline)-Mg
N-benzylhydroxylamine addition to β-aryl enoates. Enantioselective synthesis of β-aryl-β-amino acid precursors
Sibi, Mukund P.,Liu, Mei
, p. 3393 - 3396 (2007/10/03)
(matrix presented) Chiral Lewis acid catalyzed N-benzylhydroxylamine addition to pyrrolidinone-derived enoates afforded β-aryl-β-amino acid derivatives in high enantiomeric purity with moderate to very good chemical efficiency.
