97038-96-5Relevant academic research and scientific papers
Asymmetric Bromine-Lithium Exchange: Application toward the Synthesis of New Biaryl-Diphosphine Ligands
Graff, Julien,?astawiecka, Elzbieta,Guénée, Laure,Leroux, Frédéric,Alexakis, Alexandre
, p. 2833 - 2839 (2015)
The desymmetrization of the prochiral tetrabromobiphenyl via asymmetric bromine-lithium exchange as a key step of synthesis of novel biphenyl-diphosphine ligands is reported. This new approach allows an easy access to twelve new enantiomerically pure atropisomeric ligands in one- to three-step reactions in good to excellent yields.
Synthetic method for optically pure double-helix oligomeric tetra-benzocyclooctene substances
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Paragraph 0047; 0048, (2017/07/31)
The invention discloses a synthetic method for optically pure double-helix oligomeric tetra-benzocyclooctene substances. The synthetic method comprises the following steps: (1) carrying out oxidative cross-coupling on diiodo dimethoxy biphenyl (51) and 2,2',6,6'-biphenyl tetrabromide (97) to obtain 1,16-dibromo-8,9-dimethoxy tetra-benzocyclooctene (96); (2) splitting the compound (96), thus obtaining optically pure (S, S)-96 and (R, R)-96; (3) taking the compound (96) as a raw material, synthesizing an intermediate (116) containing 6 benzene rings; (4) splitting the intermediate (116) to obtain (M)-116 and (P)-116; (5) making the optically pure (S, S)-96 and (M)-116 reacted to obtain target products, namely (M) -117, (M)-149 and (M)-150; and/or: making the (R, R)-96 and (P)-116 reacted to obtain target products, namely (P)-117, (P)-149 and (P)-150.
Synthesis and Physical Properties of Strained Doubly Phosphorus-Bridged Biaryls and Viologens
Greulich, Tobias W.,Yamaguchi, Eriko,Doerenkamp, Carsten,Lübbesmeyer, Maximilian,Daniliuc, Constantin G.,Fukazawa, Aiko,Eckert, Hellmut,Yamaguchi, Shigehiro,Studer, Armido
supporting information, p. 6029 - 6033 (2017/05/08)
New P/N-containing π-electron systems comprising fully planar biaryl arrays are synthesized by multiple radical phosphanylation. The biaryl moiety in these highly strained planar π-systems is rigidified by double P-bridging. The electronic properties of the core biaryl entity are varied by introducing N-donor substituents or by installing N-atoms within the π-system, thereby moving to the viologen core structure. The electrochemical and photophysical properties of these compounds are discussed and compared with those of related systems.
Drastic change in racemization barrier upon redox reactions: Novel chiral-memory units based on dynamic redox systems
Suzuki, Takanori,Wada, Kazuhisa,Ishigaki, Yusuke,Yoshimoto, Yasuyo,Ohta, Eisuke,Kawai, Hidetoshi,Fujiwara, Kenshu
supporting information; scheme or table, p. 4100 - 4102 (2010/09/06)
The helical configuration of dication dyes 22+ with a dihydrodibenzoxepin unit remained unchanged even at high temperature, whereas the corresponding neutral electron donors 1 with a tetrahydrophenanthroxepin skeleton easily underwent racemization. Due to their electrochemical bistability, electron exchange between 1 and 22+ is prohibited. Thus, the above electrochromic pairs can serve as novel chiral-memory units where redox reactions trigger switching between an "erasable/writable"-state (1) and a "memorizing"-state (22+).
PROCESS FOR THE SYNTHESIS OF 2,2',6-TRIBROMOBIPHENYL
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Page/Page column 2, (2010/06/16)
A process for the synthesis of 2,2′,6-tribromobiphenyl.
Catalytic asymmetric bromine-lithium exchange: A new tool to build axial chirality
Perron, Quentin,Alexakis, Alexandre
supporting information; experimental part, p. 2611 - 2620 (2011/01/05)
We present here the first catalytic desymmetrization of the 2,2′,6,6′-tetrabromobiphenyl 1 and analogues, by a bromine-lithium exchange catalyzed by either diamines or diether derivatives (0.5 equiv.), yielding axially chiral compounds in high yield (up to 89%) and high enantioselectivity (up to 82%).
Chiral bromine-lithium exchange catalyzed by diamines
Perron, Quentin,Praz, Jezabel,Alexakis, Alexandre
scheme or table, p. 1004 - 1007 (2009/10/23)
Different classes of prochiral polyhalide compounds have been tested in a chiral bromine-lithium exchange in the presence of different diamines with enantiomeric excesses of up to 63%.
Process for the synthesis of 2,2 ,6-tribromobiphenyl
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Page/Page column 4, (2008/06/13)
A process for the synthesis of 2,2',6-tribromobiphenyl
PROCESS FOR THE SYNTHESIS OF 2,2',6-TRIBROMOBIPHENYL
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Page/Page column 5-6, (2008/06/13)
A process for the synthesis of 2,2',6-tribromobiphenyl.
PROCESS FOR THE PREPARATION OF ASYMMETRICALLY SUBSTITUTED BIARYLDIPHOSPHINES
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Page/Page column 15, (2008/06/13)
Provided is a process for the preparation of asymmetrically substituted biaryldiphosphine ligands of the formula, (I) wherein R1 is C1-6-alkyl or C3-10-cycloalkyl optionally substituted with one or more halogen atoms, and R2 and R3 are equal and are C5-10-cycloalkyl or C1-6-alkyl, or R2 is C5-10-cycloalkyl or C1-6-alkyl, and R3 is aryl optionally substituted with one or more substituents selected from the group consisting of halogen atoms, nitro, amino, C1-6-alkyl, C1-6-alkoxy and di-C1-6-alkylamino groups, and each C1-6-alkyl, C1-6-alkoxy, di-C1-6-alkylamino and C5-10-cycloalkyl group in R2 and R3 optionally being substituted with one or more halogen atoms, from 2,2’, 6, 6’-tetra-bromobiphenyl by a sequence of bromine-metal exchanges and subsequent reactions.

