- Rhodium-Catalyzed Deoxygenation and Borylation of Ketones: A Combined Experimental and Theoretical Investigation
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The rhodium-catalyzed deoxygenation and borylation of ketones with B2pin2 have been developed, leading to efficient formation of alkenes, vinylboronates, and vinyldiboronates. These reactions feature mild reaction conditions, a broad substrate scope, and excellent functional-group compatibility. Mechanistic studies support that the ketones initially undergo a Rh-catalyzed deoxygenation to give alkenes via boron enolate intermediates, and the subsequent Rh-catalyzed dehydrogenative borylation of alkenes leads to the formation of vinylboronates and diboration products, which is also supported by density functional theory calculations.
- Tao, Lei,Guo, Xueying,Li, Jie,Li, Ruoling,Lin, Zhenyang,Zhao, Wanxiang
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supporting information
p. 18118 - 18127
(2020/11/26)
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- Copper-catalyzed cross-coupling of vinyliodonium salts and diboron reagents to generate alkenyl boronic esters
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An efficient approach for the synthesis of alkenyl boronic esters through the copper-catalyzed cross-coupling of vinyliodonium salts and diboron reagents is reported. This method is distinguished by its mild conditions and short reaction time of less than
- Bao, Robert Li-Yuan,Gan, Shaoyan,Shi, Lei,Zhu, Dan
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supporting information
p. 5567 - 5570
(2020/08/21)
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- Development and Mechanistic Studies of Iron-Catalyzed Construction of Csp2-B Bonds via C-O Bond Activation
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Herein we describe an iron-catalyzed borylation of alkenyl and aryl carbamates through the activation of a C-O bond. This protocol exhibits high efficiency, a broad substrate scope, and the late-stage borylation of biorelevant compounds, thus providing potential applications in medicinal chemistry. Moreover, this method enables orthogonal transformations of phenol derivatives and also offers good opportunities for the synthesis of multisubstituted arenes. Preliminary mechanistic studies suggest that a FeII/FeIII catalytic cycle via a radical pathway might be involved in the reaction.
- Geng, Shasha,Zhang, Juan,Chen, Shuo,Liu, Zhengli,Zeng, Xiaoqin,He, Yun,Feng, Zhang
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supporting information
p. 5582 - 5588
(2020/07/08)
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- Catalytic enantioselective allylboration of propargylic aldehydes
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Homoallylic propargylic alcohols are important building blocks in natural product synthesis. This moiety can be transformed into various other structures by performing other known transformations, which can in turn lead to the synthesis of biologically us
- Bhakta, Urmibhusan,Sullivan, Erin,Hall, Dennis G.
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p. 678 - 683
(2014/02/14)
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- Tricyclic pyridine derivatives, medicaments containing such compounds, their use and process for their preparation
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The present invention relates to compounds defined by formula I wherein the variables R1-R8 are defined as in the description, possessing valuable pharmacological activity. Particularly, the compounds are inhibitors of cholesterol ester transfer protein (CETP) and thus are suitable for treatment and prevention of diseases which can be influenced by inhibition of this enzyme.
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Paragraph 1781; 1782; 1783
(2013/03/26)
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- 5-SUBSTITUTED 2-PHENYLQUINOLINE COMPLEXES MATERIALS FOR LIGHT EMITTING DIODE
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Compounds are provided that comprise a ligand having a 5-substituted 2-phenylquinoline. In particular, the 2-phenylquinoline may be substituted with a bulky alkyl at the 5-position. These compounds may be used in organic light emitting devices, in particular as red emitters in the emissive layer of such devices, to provide devices having improved properties.
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Page/Page column 62-63
(2012/11/13)
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- TRICYCLIC PYRIDINE DERIVATIVES, MEDICAMENTS CONTAINING SUCH COMPOUNDS, THEIR USE AND PROCESS FOR THEIR PREPARATION
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The present invention relates to compounds defined by formula I wherein the variables R1-R8 are defined as in the description, possessing valuable pharmacological activity. Particularly, the compounds are inhibitors of cholesterol ester transfer protein (CETP) and thus are suitable for treatment and prevention of diseases which can be influenced by inhibition of this enzyme.
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Page/Page column 123
(2012/03/10)
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- TRICYCLIC PYRIDINE DERIVATIVES, MEDICAMENTS CONTAINING SUCH COMPOUNDS, THEIR USE AND PROCESS FOR THEIR PREPARATION
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The present invention relates to compounds defined by formula (I), wherein the variables R1-R8 are defined as in the description, possessing valuable pharmacological activity. Particularly, the compounds are inhibitors of cholesterol
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Page/Page column 230-231
(2012/09/10)
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- Carbon-boron bond cross-coupling reaction catalyzed by -PPh2 containing palladium-indolylphosphine complexes
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This study describes the application of indolylphosphine ligands with a diphenylphosphino moiety to the palladium-catalyzed borylation of aryl chlorides. The combination of palladium metal precursor with PPh 2-Andole-phos, which comprises an inexpensive -PPh2 group, provides highly effective catalysts for the borylation of aryl chlorides. A range of functional groups such as -CN, -NO2, -CHO, -COMe, -COOMe, and -CF3 was compatible, and the catalyst loading down to 0.025 mol % of Pd can be achieved. The Pd/PPh2-Andole-phos system is able to catalyze both borylation reaction and Suzuki-Miyaura coupling reaction in a one-pot sequential manner for the direct synthesis of biaryl compounds in excellent yields.
- Chow, Wing Kin,Yuen, On Ying,So, Chau Ming,Wong, Wing Tak,Kwong, Fuk Yee
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experimental part
p. 3543 - 3548
(2012/06/15)
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- TRICYCLIC PYRIDINE DERIVATIVES, MEDICAMENTS CONTAINING SUCH COMPOUNDS, THEIR USE AND PROCESS FOR THEIR PREPARATION
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The present invention relates to compounds defined by formula (I) wherein the variables R1-R8 are defined as in the description, possessing valuable pharmacological activity. Particularly, the compounds are inhibitors of cholesterol
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Page/Page column 230-231
(2011/09/19)
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- Selective C-H borylation of alkenes by palladium pincer complex catalyzed oxidative functionalization
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(Figure Presented) The C-H borylation of simple alkenes catalyzed by palladium pincer complex 1 was performed in the presence of hypervalent iodine and bis(pinacolato)diboron compounds. The borylation reaction probably occurs by a PdIIPdIVoxidationdiboronate transmetalation sequence. TFA = trifluoroacetate.
- Selander, Nicklas,Willy, Benjamin,Szabo, Kaiman J.
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supporting information; experimental part
p. 4051 - 4053
(2010/07/05)
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- Rhodium-catalyzed dehydrogenative borylation of cyclic alkenes
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A rhodium-catalyzed dehydrogenative borylation of cyclic alkenes is described. This reaction provides direct access to cyclic 1-alkenylboronic acid pinacol esters, useful intermediates in organic synthesis. Suzuki-Miyaura cross-coupling applications are also presented. The Royal Society of Chemistry 2010.
- Kondoh, Azusa,Jamison, Timothy F.
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p. 907 - 909
(2010/06/12)
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- Functionalization of unactivated alkenes through iridium-catalyzed borylation of carbon-hydrogen bonds. Mechanism and synthetic applications
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(Chemical Equation Presented) This paper describes an efficient carbon-carbon bond formation reaction, which is based on carbon-hydrogen bond functionalization of unactivated alkenes. This process is based on in situ generation of allylic and vinylic boronates by iridium-catalyzed borylation of alkenes followed by carbon-carbon bond formation reactions. The selectivity of the carbon-hydrogen bond functionalization can be efficiently controlled for cyclic alkenes. By using additives, such as methylimidazole and DBU, the iridium-catalyzed borylation led to formation of allyl boronates, which reacted with aldehydes in a one-pot sequence affording stereodefined homoallylic alcohols. Cycloalkenes without additives aswell as acyclic substrates gave vinylic boronates, which were coupled with organohalides in a Suzuki-Miyaura sequence. By this process allylic and vinylic silabutadiene derivatives can be prepared from allylsilanes with excellent regio- and stereoselectivity. The mechanism of the carbon-hydrogen bond functionalization based on the borylation reaction was explored by isotope labeling experiments, measuring the kinetic isotope effect and study of the effects of the additives on the selectivity of the process. It was concluded that the reactions proceed via a dehydrogenative borylationmechanism,which shows analogous features with the palladium-catalyzed Heck coupling reaction.
- Olsson, Vilhelm J.,Szabo, Kalman J.
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supporting information; body text
p. 7715 - 7723
(2010/02/28)
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- An improved system for the palladium-catalyzed borylation of aryl halides with pinacol borane
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(Chemical Equation Presented) borylation of aryl halides with an inexpensive and atom-economical boron source, pinacol borane, has been developed. This system allows for the conversion of aryl and heteroaryl iodides, bromides, and several chlorides, containing a variety of functional groups, to the corresponding pinacol boronate esters. In addition to the increase in substrate scope, this is the first general method where relatively low quantities of catalyst and short reaction times can be employed.
- Billingsley, Kelvin L.,Buchwald, Stephen L.
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p. 5589 - 5591
(2008/12/20)
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- Catalytic enantioselective allyl- and crotylboration of aldehydes using chiral diol·SnCl4 complexes. Optimization, substrate scope and mechanistic investigations
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We report a novel class of C2-symmetric chiral diols derived from the hydrobenzoin skeleton. The combination of these diols with SnCl 4 under Yamamoto's concept of Lewis acid assisted Bronsted acidity (LBA catalysis) leads to high levels of asymmetric induction in the allylboration of aldehydes by commercially available allylboronic acid pinacol ester 1a. The corresponding homoallylic alcohol products of synthetically useful aliphatic aldehydes are obtained in excellent yields with up to 98:2 er. This combined acid manifold is also efficient in catalyzing the diastereo- and enantioselective crotylboration of aldehydes, thus providing the propionate units in >95:5 dr and up to 98:2 er. The X-ray crystal structure of the optimal diol·SnCl4 complex, Vivol (4m)·SnCl 4, unambiguously shows the Bronsted acidic character of this LBA catalyst and its highly dissymmetrical environment. Further controls have ruled out a possible boron transesterification mechanism with the chiral diol and point to LBA catalyst-derived activation of the pinacol allylic boronates 1. Due to slow dissociation of the diol·SnCl4 complex, a small excess of diol is required in order to suppress a competing racemic cycle catalyzed by free SnCl4.
- Rauniyar, Vivek,Zhai, Huimin,Hall, Dennis G.
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supporting information; experimental part
p. 8481 - 8490
(2009/02/02)
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- Convenient preparation of cycloalkenyl boronic acid pinacol esters
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A practical method for the preparation of cycloalkenyl boronic acid pinacol esters is described. These important synthetic intermediates are typically made using more expensive methods like transition metal-catalyzed borylation of alkenyl halides or trifl
- Rauniyar, Vivek,Zhai, Huimin,Hall, Dennis G.
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experimental part
p. 3984 - 3995
(2009/04/11)
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- Palladium-catalyzed borylation of aryl chlorides: Scope, applications, and computational studies
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(Chemical Equation Presented) From chloride to boronate: Catalysts comprising palladium and biaryl monophosphine ligands provide highly active systems for the borylation of aryl and heteroaryl chlorides (see scheme). Symmetrical and unsymmetrical biaryl products can also be prepared directly from two aryl chlorides without isolation of the intermediate boronate esters. Computational studies provide insight into the roles of the biaryl phosphine ligand and the KOAc base in the catalytic cycle.
- Billingsley, Kelvin L.,Barder, Timothy E.,Buchwald, Stephen L.
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p. 5359 - 5363
(2008/03/18)
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- Palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron with 1-alkenyl halides or triflates: Convenient synthesis of unsymmetrical 1,3-dienes via the borylation-coupling sequence
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The synthesis of 1-alkenylboronic acid pinacol esters via a palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron (pin2B2, pin = Me4C2O2) with 1-alkenyl halides or triflates was carrie
- Takagi, Jun,Takahashi, Kou,Ishiyama, Tatsuo,Miyaura, Norio
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p. 8001 - 8006
(2007/10/03)
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- Synthesis of alkenylboronates via palladium-catalyzed borylation of alkenyl triflates (or Iodides) with pinacolborane
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Various alkenyl iodides and triflates were borylated with pinacolborane in the presence of Et3N and a catalytic amount of PdCl2(dppf) and AsPh3 to afford the corresponding alkenylboronates in good yields.
- Murata, Miki,Oyama, Takashi,Watanabe, Shinji,Masuda, Yuzuru
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p. 778 - 780
(2007/10/03)
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