cas 67081-98-5, 1-[4-(TRIFLUOROMETHYL)PHENYL]PROPAN-1-OL

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NOVEL COMPOUNDS
The invention relates to compounds of formula (I) and to their use in treating or preventing an inflammatory disease or a disease associated with an undesirable immune response: wherein R, R1, R2 and RB are as defined herein.
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(2022/03/07)

Novel non-metal catalyst for catalyzing asymmetric hydrogenation of ketone and alpha, beta-unsaturated ketone
The invention discloses a novel non-metal catalyst for catalyzing asymmetric hydrogenation of ketone and alpha, beta-unsaturated ketone. The preparation method of a chiral alcohol compound shown as formula IV comprises the following step of: reacting a ketone compound shown as formula V with hydrogen under the catalysis of tri(4-hydrotetrafluorophenyl)boron and a chiral oxazoline compound to obtain the chiral alcohol compound shown as the formula IV; the preparation method of a chiral tetralone compound shown as formula VI comprises the following step of: under the catalysis of tri(4-hydrotetrafluorophenyl)boron and a chiral oxazoline compound, reacting an alpha, beta-unsaturated ketone compound shown as formula VII with hydrogen to obtain the chiral tetralone compound shown as the formula VI. The method has the advantages of easy synthesis of raw materials, mild reaction conditions, simple operation, high stereoselectivity and the like, the ee value of the product is up to 92%, and the yield is up to 99%.
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Paragraph 0162-0167

(2021/04/26)

2,2′-Bipyridine-α,α′-trifluoromethyl-diol ligand: Synthesis and application in the asymmetric Et2Zn alkylation of aldehydes
A chiral 2,2′-bipyridine ligand (1) bearing α,α′-trifluoromethyl-alcohols at 6,6′-positions was designed in five steps affording either the R,R or S,S enantiomer with excellent stereoselectivities, i.e. 97% de, >99% ee and >99.5% de, >99.5% ee, respectively. The key step for reaching high levels of stereoselectivity was demonstrated to be the resolution of the α-CF3-alcohol using (S)-ibuprofen as the resolving agent. An initial application for the 2,2′-bipyridine-α,α′-CF3-diol ligand was highlighted in the ZnII-catalyzed asymmetric ethylation reaction of aromatic, heteroaromatic, and aliphatic aldehydes. Synergistic electron deficiency and steric hindrance properties of the newly developed ligand afforded the corresponding alcohols in good to excellent yields (up to 99%) and enantioselectivities (up to 95% ee). As observed from single crystal diffraction analysis, the complexation of the 2,2′-bipyridine-α,α′-CF3-diol ligand generates an unusual hexacoordinated ZnII.
Lauzon, Samuel,Ollevier, Thierry
supporting information
p. 11025 - 11028
(2021/11/03)

Asymmetric Hydrogenation of Ketones and Enones with Chiral Lewis Base Derived Frustrated Lewis Pairs
The concept of frustrated Lewis pairs (FLPs) has been widely applied in various research areas, and metal-free hydrogenation undoubtedly belongs to the most significant and successful ones. In the past decade, great efforts have been devoted to the synthesis of chiral boron Lewis acids. In a sharp contrast, chiral Lewis base derived FLPs have rarely been disclosed for the asymmetric hydrogenation. In this work, a novel type of chiral FLP was developed by simple combination of chiral oxazoline Lewis bases with achiral boron Lewis acids, thus providing a promising new direction for the development of chiral FLPs in the future. These chiral FLPs proved to be highly effective for the asymmetric hydrogenation of ketones, enones, and chromones, giving the corresponding products in high yields with up to 95 % ee. Mechanistic studies suggest that the hydrogen transfer to simple ketones likely proceeds in a concerted manner.
Du, Haifeng,Feng, Xiangqing,Gao, Bochao,Meng, Wei
supporting information
p. 4498 - 4504
(2020/02/05)

Enantioselective Addition of Diethylzinc to Aromatic Aldehydes Using Novel Thiophene-Based Chiral Ligands
Abstract: Chiral norephedrine-derived β-amino alcohols with a thiophene moiety were synthesized from thiophene carbaldehydes (methyl- or ethyl-substituted) and chiral amino alcohols, such as both enantiomers of norephedrine and 2-aminopropanol. The synthesized ligands were applied to the catalytic asymmetric addition of diethylzinc to aldehydes to obtain optically active alcohols with a high conversion (92%) and excellent enantioselectivities (ee up to 99%). The highest enantioselectivity (ee 99%) was obtained with p-trifluorobenzaldehyde as the substrate containing the strongly electron-acceptor CF3 group.
Aydin, A. E.
p. 901 - 909
(2020/07/03)

Observation of hyperpositive non-linear effect in catalytic asymmetric organozinc additions to aldehydes
Asymmetric amplification is a phenomenon that is believed to play a key role in the emergence of homochirality in life. In asymmetric catalysis, theoretical and experimental models have been investigated to provide an understanding of how chiral amplification is possible, in particular based on non-linear effects. Interestingly, it has been proposed a quarter century ago that chiral catalysts, when not enantiopure might even be more enantioselective than their enantiopure counterparts. We show here that such hyperpositive non-linear effect in asymmetric catalysis is indeed possible. An in-depth study into the underlying mechanism was carried out, and the scheme we derive differs from the previous proposed models.
Geiger, Yannick,Achard, Thierry,Maisse-Fran?ois, Aline,Bellemin-Laponnaz, Stéphane
supporting information
p. 1250 - 1256
(2020/07/25)

Chiral zinc amidate catalyzed additions of diethylzinc to aldehydes
A series of bifunctional spiro ligands bearing “carboxamide–phosphine oxide” groups and ethylzinc carboxamidates from these ligands as catalysts for Et2Zn additions to aldehydes were reported. Excellent yields were obtained with moderate ee′s in Et2Zn additions to benzaldehyde derivatives, implying effectiveness of our newly designed catalytic structures as well as mediocre stereocontrol by these chiral ligands. Possible transition states were suggested based on the crystal structures of two ligands.
Zhang, Jinxia,Li, Shasha,Zheng, Xinxin,Li, Hongjie,Jiao, Peng
supporting information
p. 1913 - 1917
(2019/06/24)

Noscapine Derivatives as New Chiral Catalysts in Asymmetric Synthesis: Highly Enantioselective Addition of Diethylzinc to Aldehydes
Noscapine, a natural alkaloid, has never been used as a parent scaffold in chiral induction. The first examples of noscapinoid compounds as efficient catalysts in asymmetric synthesis are now reported. Three derivatives of noscapine were synthesized from its reaction with different Grignard reagents. Asymmetric addition of diethylzinc to aldehydes was performed in the presence of these catalysts in high yields and good to excellentees.
Mohebbi, Maryam,Bararjanian, Morteza,Ebrahimi, Samad N.,Smie?ko, Martin,Salehi, Peyman
p. 1841 - 1848
(2018/02/14)

Chiral 2-(2-hydroxyaryl)alcohols (HAROLs) with a 1,4-diol scaffold as a new family of ligands and organocatalysts
Efficient and modular syntheses of chiral 2-(2-hydroxyaryl)alcohols (HAROLs), novel 1,4-diols carrying one phenolic and one alcohol hydroxyl group, have been developed which led to generation of a small library of structurally diverse HAROLs in enantiomerically pure form. Of the different HAROLs examined, a HAROL based on the indan backbone exhibited the highest activity and enantioselectivity in the 1,2-addition of certain organometallic compounds to aldehydes in the presence of Ti(OiPr)4 (up to 97% y, 88% ee) and performed as a hydrogen-bond donor organocatalyst in the Morita-Baylis-Hillman reaction, promoted by trialkylphosphines.
Dilek, ?mer,Tezeren, Mustafa A.,Tilki, Tahir,Ertürk, Erkan
supporting information
p. 268 - 286
(2017/12/06)

New C2-symmetric six-membered carbene ligands for asymmetric diethylzinc addition of arylaldehydes
A series of new six-membered NHC precursors were prepared by simply esterification of their parent compounds. Their applicability in asymmetric diethylzinc addition of arylaldehydes has been demonstrated and the corresponding secondary alcohol was obtained with good yields and moderate enantioselectivities. (Figure pressented)
Zhou, Bihui,Li, Zijing,Yang, Chen,Li, Linlin,Fan, Limei,Huang, Hongxia,Li, Jie
p. 1 - 10
(2018/06/27)

Halogen-bonded iodonium ion catalysis: A route to α-hydroxy ketones: Via domino oxidations of secondary alcohols and aliphatic C-H bonds with high selectivity and control
A domino synthesis of α-hydroxy ketones has been developed from benzylic secondary alcohols employing catalytic iodonium ions stabilized by DMSO. The reaction proceeds through an unprecedented sequential oxidation of alcohols to ketone and its α-hydroxylation in a controlled manner. The spectroscopic evidence establishes the possibility of formation of a stable halogen-bonded adduct between DMSO and iodonium ions.
Guha, Somraj,Kazi, Imran,Mukherjee, Pranamita,Sekar, Govindasamy
supporting information
p. 10942 - 10945
(2017/10/13)

Stereoselective amination of racemic sec-alcohols through sequential application of laccases and transaminases
A one-pot/two-step bienzymatic asymmetric amination of secondary alcohols is disclosed. The approach is based on a sequential strategy involving the use of a laccase/TEMPO catalytic system for the oxidation of alcohols into ketone intermediates, and their following transformation into optically enriched amines by using transaminases. Individual optimizations of the oxidation and biotransamination reactions have been carried out, studying later their applicability in a concurrent process. Therefore, 17 racemic (hetero) aromatic sec-alcohols with different substitutions in the aromatic ring have been converted into enantioenriched amines with good to excellent selectivities (90-99% ee) and conversion values (67-99%). The scalability of the process was also demonstrated when two different amine donors were used in the transamination step, such as isopropylamine and cis-2-buten-1,4-diamine. Satisfyingly, both sacrificial amine donors can shift the equilibrium toward the amine formation, leading to the corresponding isolated enantioenriched amines with good to excellent results.
Martínez-Montero, Lía,Gotor, Vicente,Gotor-Fernández, Vicente,Lavandera, Iván
supporting information
p. 474 - 480
(2017/06/23)

Umpolung Synthesis of 1,3-Amino Alcohols: Stereoselective Addition of 2-Azaallyl Anions to Epoxides
We report the direct preparation of 1,3-amino alcohols that contain up to three contiguous stereogenic centers by the umpolung coupling of imines and epoxides. Nucleophilic 2-azaallyl anions, generated from imines, are stereoselectively added to epoxides to furnish 1,3-amino alcohols after hydrolysis of the product imine. Transformations afford amino alcohols with >98% site selectivity with respect to both reaction partners and in up to >98% yield and >20:1 dr.
Daniel, Paige E.,Weber, Alexandria E.,Malcolmson, Steven J.
supporting information
p. 3490 - 3493
(2017/07/15)

Third-Generation Amino Acid Furanoside-Based Ligands from d-Mannose for the Asymmetric Transfer Hydrogenation of Ketones: Catalysts with an Exceptionally Wide Substrate Scope
A modular ligand library of α-amino acid hydroxyamides and thioamides was prepared from 10 different N-tert-butyloxycarbonyl-protected α-amino acids and three different amino alcohols derived from 2,3-O-isopropylidene-α-d-mannofuranoside. The ligand library was evaluated in the half-sandwich ruthenium- and rhodium-catalyzed asymmetric transfer hydrogenation of a wide array of ketone substrates, including simple as well as sterically demanding aryl alkyl ketones, aryl fluoroalkyl ketones, heteroaromatic alkyl ketones, aliphatic, conjugated and propargylic ketones. Under the optimized reaction conditions, secondary alcohols were obtained in high yields and in enantioselectivities up to >99%. The choice of ligand/catalyst allowed for the generation of both enantiomers of the secondary alcohols, where the ruthenium-hydroxyamide and the rhodium-thioamide catalysts act complementarily towards each other. The catalytic systems were also evaluated in the tandem isomerization/asymmetric transfer hydrogenation of racemic allylic alcohols to yield enantiomerically enriched saturated secondary alcohols in up to 98% ee. Furthermore, the catalytic tandem α-alkylation/asymmetric transfer hydrogenation of acetophenones and 3-acetylpyridine with primary alcohols as alkylating and reducing agents was studied. Secondary alcohols containing an elongated alkyl chain were obtained in up to 92% ee. (Figure presented.).
Margalef, Jèssica,Slagbrand, Tove,Tinnis, Fredrik,Adolfsson, Hans,Diéguez, Montserrat,Pàmies, Oscar
p. 4006 - 4018
(2016/12/30)

Enantioselective addition of organozinc reagents to carbonyl compounds catalyzed by a camphor derived chiral γ-amino thiol ligand
In this article, the design and synthesis of the chiral camphor derived γ-amino thiol ligand 17 and its application in catalytic enantioselective carbon-carbon forming reactions through the addition of organozinc reagents to carbonyl compounds is described. The catalytic activity and enantioselectivity of ligand 17 is demonstrated in the enantioselective addition of various organozinc reagents to aldehydes and ketoesters, offering the corresponding alcohols in high yields and enantioselectivities. The role of the mercapto group in the highly enantioselective 1,2-addition reaction of organozincs to aldehyde is also discussed.
Wu, Hsyueh-Liang,Wu, Ping-Yu,Cheng, Ying-Ni,Uang, Biing-Jiun
p. 2656 - 2665
(2016/05/10)

Dual enantioselective control using D-phenylglycine-L-proline-derived catalysts for the enantioselective addition of diethylzinc to aldehyde
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Kang, Seock Yong,Park, Yong Sun
p. 108 - 111
(2016/01/20)

Asymmetric transfer hydrogenation of secondary allylic alcohols
Racemic secondary allylic alcohols were transformed into optically active secondary alcohols by a combined Rucatalyzed isomerization/asymmetric transfer-hydrogenation reaction. The catalyst was generated in situ in isopropyl alcohol from di-μ-chlorobis[(p-cymene)chlororuthenium(II)], the chiral ligand (1S,2S)-N-(p-tolylsulfonyl)-1,2-diphenylethylenediamine, and K2CO3, and the products were afforded in yields up to 97% with up to 93% enantiomeric excess without the use of hydrogen gas. A Hammett study revealed that the reaction rate was enhanced with electronwithdrawing aryl substituents. The reaction supports the recent work published by Adolfsson et al. as new methodology for the synthesis of chiral compounds from allylic alcohols.
Shoola, Christopher O.,DelMastro, Thomas,Wu, Ruoqiu,Sowa, John R.
supporting information
p. 1670 - 1673
(2015/05/27)

Enantioselectivity switch controlled by N,N′-di- or N,N,N′,N′-tetra-substituted chiral thiophosphorodiamide ligands, structural relatives of thioureas, in catalytic additions of diethylzinc to aldehydes
We have developed a series of new chiral thiophosphorodiamide ligands derived from (1R,2R)-(+)-1,2-diphenylethylenediamine, which are the structural relatives of thioureas. An investigation into their catalytic properties in asymmetric additions of diethylzinc to aldehydes has shown that N,N,N′,N′-tetra-substituted chiral thiophosphorodiamides can give (R)-secondary alcohols with up to 98% yield and 98% ee, while N,N′-di-substituted chiral thiophosphorodiamides give (S)-secondary alcohols with up to 99% yield and 97% ee values. The enantioselectivity switch is highly efficient with a broad substrate scope. We have also proposed hypothetical reaction pathways, which result in an enantioselectivity switch.
Yue, Huifeng,Huang, Huayin,Bian, Guangling,Zong, Hua,Li, Fangling,Song, Ling
p. 170 - 180
(2014/02/14)

Design of novel chiral N,N,O-tridentate phenanthroline ligands and their application to enantioselective addition of organozinc reagents to aldehydes
The novel N,N,O-tridentate phenanthroline ligand (BinThro) bearing an axially chiral binaphthyl backbone prepared from BINOL was found to be an effective chiral catalyst for enantioselective addition of diethylzinc to aromatic aldehydes with high enantios
Naganawa, Yuki,Namba, Tomoya,Aoyama, Tomotaka,Shoji, Kentaro,Nishiyama, Hisao
p. 13224 - 13227
(2015/05/20)

Vasicine as tridentate ligand for enantioselective addition of diethylzinc to aldehydes
The first report of natural l-vasicine as tridentate chiral ligand for the enantioselective addition of diethylzinc to a variety of aliphatic and aromatic aldehydes is described. The ligand generates R-isomer of the secondary alcohols upto 98% ee. The qui
Aga, Mushtaq A.,Kumar, Brijesh,Rouf, Abdul,Shah, Bhahwal A.,Taneja, Subhash C.
supporting information
p. 2639 - 2641
(2014/05/06)

Synergistic effect of achiral quaternary ammonium salt on asymmetric additions of diethylzinc to aldehydes
Our investigation has shown that achiral quaternary ammonium salt has a significant synergistic effect on the asymmetric additions of diethylzinc to aldehydes catalyzed by chiral phosphoramide-Zn(II) complex. The addition of 10 mol % NBu4X can dramatically reduce the loading amount of chiral ligand without sacrificing the excellent reactivity and enantioselectivity of the asymmetric reaction.
Zong, Hua,Huang, Huayin,Bian, Guangling,Song, Ling
supporting information
p. 2722 - 2725
(2013/06/26)

Highly efficient asymmetric additions of diethylzinc to aldehydes triply activated by chiral phosphoramide-Zn(II) complexes derived from cinchona alkaloids
New chiral phosphoramide ligands derived from cinchona alkaloids were developed, which react with diethylzinc to form chiral phosphoramide-Zn(II) complexes containing two Lewis bases and one Lewis acid. These trifunctional complexes can serve as highly efficient chiral catalysts for triple activation of enantioselective addition reactions of diethylzinc with aldehydes to give desired alcohol products with excellent yields and enantiomeric excess (ee) values up to 99%. 2013 Wiley Periodicals, Inc.
Shen, Bin,Huang, Huayin,Bian, Guangling,Zong, Hua,Song, Ling
p. 561 - 566
(2013/09/12)

Asymmetric preparation of new N, N -dialkyl-2-amino-1,1,2-triphenylethanol catalysts and a kinetic resolution in the addition of diethylzinc to flavene-3-carbaldehydes
Enantiopure N,N-dialkyl-(S)-2-amino-1,1,2-triphenylethanols were prepared using a new synthetic methodology and tested for their ability to catalyze the enantioselective addition of diethylzinc to aldehydes. The structural modification of N-substituents of the catalysts led us to identify N-methyl-N-(S)-1-phenyl-ethyl-substituted 4d as an effective catalyst for the addition. Also disclosed is a kinetic resolution of racemic flavene-3- carbaldehydes with the chiral catalyst.
Kang, Seockyong,Baek, Jinho,Ko, Yikyung,Im, Chan,Park, Yongsun
supporting information
p. 630 - 634
(2013/04/23)

Modular prolinol chiral ligands for enantioselective addition of diethylzinc to aromatic aldehydes
Enantioselective addition of diethylzinc (ZnEt2) to a series of aromatic aldehydes was promoted using a modular prolinol chiral ligand, 2-(S)-2-(hydroxydiphenylmethyl)pyrrolidin-1-yl)methyl)-4-nitrophenol (1a), without using titanium complex. The catalytic system employing 15 mol% of 1a was found to promote the addition of diethylzinc to a wide range of aromatic aldehydes with electron-donating and electron-withdrawing substituents, giving up to 86% ee of the corresponding secondary alcohol under mild conditions.
Gou, Shaohua,Ye, Zhongbin,Feng, Mingming,Jiang, Wenchao
p. 941 - 950
(2013/02/25)

CAMPHOR-DERIVED COMPOUNDS, METHOD FOR MANUFACTURING THE SAME, AND APPLICATION THEREOF
Camphor-derived compounds are disclosed, which are represented as the following formula (I): wherein R1, R2, R3, and R4 each are defined as described in the specification. In addition, a method for manufacturing the camphor-derived compounds and application thereof are disclosed.
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(2012/04/05)

Enantioselective addition of dialkylzincs to aldehydes catalyzed by (-)-MITH
An effective catalytic system that imparts high enantioselectivity has been disclosed for the synthesis of optically active alcohols, which may undergo further chemical transformations. The enantioselective alkylation of aldehydes with dialkylzincs to afford the corresponding optically active alcohols with excellent enantioselectvities has been achieved in the presence of 0.1-0.5 mol % of the camphor-derived chiral ligand (-)-2-exo-morpholinoisobornane-10-thiol (MITH) (1) at room temperature or at 0 °C. I zinc so too: The enantioselective alkylation of aldehydes with dialkylzincs yielded the desired alcohol products with up to 99 % ee in the presence of 0.1-0.5 mol % of ligand (-)-2-exo-morpholinoisoborne-10-thiol (1) at room temperature or at 0°C. Copyright
Cheng, Ying-Ni,Wu, Hsyueh-Liang,Wu, Ping-Yu,Shen, Ying-Ying,Uang, Biing-Jiun
supporting information
p. 2921 - 2924
(2013/02/22)

Asymmetric preparation of d-phg-l-pro dipeptide-derived chiral ligands for enantioselective addition of diethylzinc to aldehydes
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Kang, Seock Yong,Ko, Yi Kyung,Park, Kon Ji,Park, Yong Sun
experimental part
p. 2397 - 2400
(2012/08/28)

L-alanine-derived chiral ligands for asymmetric addition of diethylzinc to aldehydes
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Kang, Seock Yong,Baek, Jinho,Kang, Kyoung Hee,Lee, Jeong-Ae,Park, Yong Sun
p. 3125 - 3128
(2012/10/30)

The syntheses of new camphorsulfonylated ligands derived from 2-amino-2'-hydroxy-1,1'-binaphthyl and their enantioselectivities in the addition of dialkylzinc reagents to aldehydes
A series of new camphorsulfonylated ligands derived from chiral 2-amino-2'-hydroxy-1,1'-binaphthyl (NOBIN) and (+)-camphorsulfonic acid were synthesized by a short and simple synthetic sequence, and their enantioselective catalytic activities were assessed in the nucleophilic addition reaction of dialkylzinc reagents to aldehydes in the presence of titanium tetraisopropoxide. The most efficient ligand, N-hydroxycamphorsulfonylated (S)-NOBIN, gave (S)-addition products with good yields and up to 87% of ee value. The 1H nuclear magnetic resonance (NMR) and 13C NMR results of the titanium titration experiments on this ligand indicate that the most likely catalytic reactive species involved in this catalytic asymmetric addition is a bimetallic titanium complex. A possible catalytic reaction mechanism is proposed. Copyright
Bian, Guangling,Huang, Huayin,Zong, Hua,Song, Ling
p. 825 - 832
(2012/11/07)

Cluster-organic framework materials as heterogeneous catalysts for high efficient addition reaction of diethylzinc to aromatic aldehydes
To explore the catalytic activity of heterometallic cluster-organic frameworks, three 3d-3d heterometallic cluster-organic frameworks based on the cooperative assembly of tetrahedral Cu4I4 and metal-carboxylate clusters with potential open metal sites were synthesized and described in detail. The structure of 1 consists of tetrahedral [Cu 4I4(INA)4]4- metalloligands (INA = isonicotinate) linking unusual Zn8(μ4-O)(COO) 12(H2O)4 clusters into a (4,12)-connected network. Compound 2 features a 2-fold interpenetrating 4-connected bbf-type framework based on new [Cu4I4(INA)2(DBO) 2]2- metalloligands (DBO = 1,4-diazabicyclo[2.2.2]octane) and paddle-wheel Zn2(COO)4 units. The 2-fold interpenetrating diamond-type framework 3 is constructed from tetrahedral [Cu4I4(INA)4]4- metalloligand and Mn2(COO)4(H2O)2(DMF) unit with potential open Mn centers. All three framework materials have notable catalytic activity on the diethylzinc addition to aromatic aldehydes, and the catalytic properties of compound 1 have been studied in detail. The results reveal that the heterogeneous catalysis of the diethylzinc addition to aromatic aldehydes by using cluster-organic framework as catalyst is determined by several experimental factors, such as temperature, reaction time, and the incorporation of electron-withdrawing groups in aromatic aldehydes.
Tan, Yan-Xi,He, Yan-Ping,Zhang, Jian
p. 4711 - 4716
(2013/03/13)

Sugar-monophosphite ligands applied to the asymmetric Ni-catalyzed trialkylaluminum addition to aldehydes
A series of readily available sugar-based phosphite ligands were applied to the Ni-catalyzed asymmetric trialkylaluminum additions to aldehydes. The ability of the catalysts to transfer chiral information to the product could be tuned by choosing suitable ligand components (configuration at C-3 of the furanoside backbone; the steric hindrance of the substituent at C-3 and the substituents/configuration of the biaryl phosphite moieties). Good enantioselectivities (ee's up to 84%) were obtained for several aryl aldehydes using several organoaluminum sources.
Alegre, Sabina,Dieguez, Montserrat,Pmies, Oscar
experimental part
p. 834 - 839
(2011/08/22)

Switching of enantioselectivity in the catalytic addition of diethylzinc to aldehydes by regioisomeric chiral 1,3-amino sulfonamide ligands
Twenty chiral 1,3-amino sulfonamides of two classes (2a-i and 3a-k) have been prepared from (-)-cis-2-benzamidocyclohexanecarboxylic acid (1) and studied as ligands for catalytic enantioselective addition of Et2Zn to a variety of aromatic and aliphatic aldehydes. The ligands 2 and 3 are regioisomers in which the position of the amine and sulfonamide groups is exchanged. Each class of ligands with the same chirality was shown to afford sec-alcohols with the opposite stereochemistry. Structural surveys revealed that the combination of tertiary amino and p-toluenesufonylamido groups works most effectively for the reaction. Through optimization of the structural and reaction conditions, the best ligands quantitatively provided both enantiomeric secondary alcohols in good to excellent enantioselectivity of up to 94% and 98% ee for (S)- and (R)-enantiomers, respectively.
Hirose, Takuji,Sugawara, Kazuyuki,Kodama, Koichi
experimental part
p. 5413 - 5428
(2011/08/05)

Acetyl-BINOL as mimic for chiral β-diketonates: A building block for new modular ligands
α-Acetyl-(S)-BINOL was prepared by ortho-lithiation and subsequent acetylation of acetal-protected (S)-BINOL. The β-hydroxyketone moiety of this compound is herein a structural mimic for a β-diketonate and forms six-membered chelates with transition metal ions. The second hydroxy-function was submitted to esterification with several carboxylic acids bearing another donor function, thus, new tridentate chiral ligands were obtained. Out of this library the l-proline-α-acetyl-(S)-BINOL-ester was identified to be most effective for the titanium-mediated addition of Et2Zn to PhCHO yielding the respective secondary alcohol with up to 93% ee, which is better than with using (S)-BINOL itself. Besides a solvent dependency (use of MeCN is optimal), the proper choice of the counter-ion is crucial: anion exchange of bromide by trifluoroacetate gave a significant increase of enantioselectivity. Copyright
Von R?nn, Robert,Christoffers, Jens
scheme or table
p. 334 - 338
(2011/03/18)

Modular amino acid amide chiral ligands for enantioselective addition of diethylzinc to aromatic aldehydes
Enantioselective addition of diethylzinc to a series of aromatic aldehydes was developed using a modular amino acid amide chiral ligand (2S)-3-phenyl-N-((R)-1-phenyl-ethyl)-2-(tosylamino)propanamide without using titanium complex. The catalytic system employing 10 mol% of 1g was found to promote the addition of diethylzinc (ZnEt2) to a wide range of aromatic aldehydes with electron-donating and electron-withdrawing substituents, giving up to 82% ee of the corresponding secondary alcohol under mild conditions.
Gou, Shaohua,Ye, Zhongbin,Chang, Jing,Gou, Guangjun,Feng, Mingming
experimental part
p. 448 - 453
(2012/02/03)

Modular amino acids and β-amino alcohol-based chiral ligands for enantioselective addition of diethylzinc to aromatic aldehydes
Enantioselective addition of diethylzinc to a series of aromatic aldehydes was developed using a modular amino acids and ${bf beta}$-amino alcohol-based chiral ligand (2R)-N-[(1R,2S)-1-hydroxy-1-phenylpropan-2-yl]-3- phenyl-2-(tosylamino) propanamide (1f) without using titanium complex. The catalytic system employing 15 mol% of 1f was found to promote the addition of diethylzinc (ZnEt2) to a wide range of aromatic aldehydes with electron-donating and electron-withdrawing substituents, giving up to 97% ee of the corresponding secondary alcohol under mild conditions.
Gou, Shaohua,Ye, Zhongbin,Gou, Guangjun,Feng, Mingming,Chang, Jing
experimental part
p. 110 - 116
(2012/06/18)

Transformation of α-substituted propanols into γ-amino alcohols through nickel-catalyzed amination on the terminal γ-carbon of propanols
A nickel-phosphine complex was found to be effective as the catalyst for the transformation of alcohols into β-enaminones, which was successively converted into γ-amino alcohols by a conventional reductant. The sequential transformation is equivalent to the carbon-nitrogen bond formation at the γ-position of saturated alcohols. Georg Thieme Verlag Stuttgart · New York.
Ueno, Satoshi,Usui, Kazumi,Kuwano, Ryoichi
supporting information; experimental part
p. 1303 - 1307
(2011/07/08)

Perhydro-1,3-benzoxazines derived from (-)-8-aminomenthol as ligands for the catalytic enantioselective addition of diethylzinc to aldehydes
The catalytic potency of a series of perhydro-1,3-benzoxazines prepared from (-)-8-aminomenthol was examined in the enantioselective addition of diethylzinc to aldehydes. When (2R,3S,3aS,4aR,6R,8aS)-2-isopropyl-6,9,9- trimethyl-3-phenyldecahydro-4aH-pyrrolo[2,1-b][1,3]benzoxazin-3-ol 7b was used as a chiral ligand, 1-substituted propanols with an (R)-configuration were obtained in high yields and enantiomeric excesses up to >99%. The catalyst can be recovered and used without any loss in its activity.
Andres, Celia,Infante, Rebeca,Nieto, Javier
experimental part
p. 2230 - 2237
(2010/11/04)

Structurally constrained C1-1,1′-bisisoquinoline-based chiral ligands: geometrical implications on enantioinduction in the addition of diethylzinc to aldehydes
New highly constrained chiral C1-1,1′-bisisoquinoline ligands have been synthesized. X-ray crystallographic analysis of these ligands showed peculiar structural differences between the parent 1′,2′,3′,4′-tetrahydro-1,1′-bisisoquinolin e and its alkyl, acyl and sulfonyl derivatives. The consequences of their geometrical conformations on enantioinduction were examined by employing the enantioselective addition of diethylzinc to aldehydes. Such conformations greatly affected the catalytic efficiency of these ligands.
Qi, Gao,Judeh, Zaher M.A.
experimental part
p. 429 - 436
(2010/07/02)

Synthesis and application of 3-substituted (S)-binol as chiral ligands for the asymmetric ethylation of aldehydes
A series of (S)-BINOL ligands substituted at the 3 position with some five-membered nitrogen-containing aromatic heterocycles were effectively prepared and their catalytic abilities were evaluated in the asymmetric addition of diethylzinc to benzaldehyde in the presence of titanium tetraisopropoxide. Under the optimized reaction conditions, titanium complex of (S)-3-(1H-benzimidazol-1-yl)-1,1′-bi-2-naphthol was found to be the most efficient catalyst for asymmetric ethylation of various aldehydes to generate the corresponding secondary alcohols in up to 99% yield and 91% ee.
Zhang, Zhi-Guang,Dong, Zhi-Bing,Li, Jin-Shan
experimental part
p. 820 - 826
(2010/11/21)

(R)-(+)-binol-functionalized mesoporous organosilica as a highly efficient pre-chiral catalyst for asymmetric catalysis
(R)-(+)-Binol-functionalized chiral periodic mesoporous organosili-cas (PMOs) with different framework compositions were successfully synthesized by cocondensation of (R)-2,2′-di(methoxymethyl)oxy-6,6'-di(1-propyl- trimethoxysilyl)-1,1'-binaphthyl (BSBi-n
Liu, Xiao,Wang, Peiyuan,Yang, Yan,Wang, Peng,Yang, Qihua
scheme or table
p. 1232 - 1239
(2011/07/08)

Furanoside phosphite-phosphoroamidite: new ligand class for the asymmetric nickel-catalyzed trialkylaluminium addition to aldehydes
We have described the first successful application of bidentate ligands in the asymmetric Ni-catalyzed trialkylaluminium addition to several aldehydes. The ligands are prepared from inexpensive d-(+)-xylose and d-(+)-glucose and have the advantage of carbohydrate and phosphite/phosphoroamidite moieties. After systematic variation of the position of the phosphoroamidite group at either C5 or C-3, the configuration of C-3 and the substituents in the biaryl phosphite/phosphoroamidite moieties, enantioselectivities up to 84% and high yields were obtained in the Ni-catalyzed trialkylaluminium addition to several aldehydes.
Raluy, Eva,Diéguez, Montserrat,Pàmies, Oscar
experimental part
p. 4495 - 4497
(2009/11/30)

Screening of a modular sugar-based phosphoroamidite ligand library in the asymmetric nickel-catalyzed trialkylaluminium addition to aldehydes
A modular sugar-based phosphoroamidite ligand library for the Ni-catalyzed trialkylaluminium addition to aldehydes has been synthesized and screened. After systematic variation of the sugar backbone, the substituents at the phosphoroamidite moieties and the flexibility of the ligand backbone, the monophosphoroamidite ligand 3-amine-3-deoxy-1,2:5,6-di-O-isopropylidene-((3,3′-di-trimethylsilyl-1,1′-biphenyl-2,2′-diyl)phosphite)-α-d-glucofuranose 1d were found to be optimal. Activities were high and enantioselectivities were good (ees up to 78%) for several aryl aldehydes.
Raluy, Eva,Dieguez, Montserrat,Pamies, Oscar
experimental part
p. 1575 - 1579
(2009/12/01)

Enantioselective addition of diethylzinc to aromatic aldehydes catalyzed by Ti(IV) complexes of C2-symmetrical chiral BINOL derivatives
Enantioselective addition of diethylzinc to a series of aromatic aldehydes is developed using new chiral C2-symmetric ligand (S)-2,2′-(1,1′-binaphthyl-2,2′-diylbis(oxy))bis(methyl ene)bis(4-nitrophenol) (S)-2b. The catalytic system employing 10 mol % of (S)-2b and 120 mol % of Ti(OiPr)4 was found to promote the addition of diethylzinc to a wide range of aromatic aldehydes with electron-donating and electron-withdrawing substituents, giving up to 89% ee and up to 95% yield of the corresponding secondary alcohol under mild conditions.
Gou, Shaohua,Judeh, Zaher M.A.
scheme or table
p. 281 - 283
(2009/04/11)

Synthesis of chiral sulfamide-amine alcohol ligands for enantioselective alkylation of aldehydes
A series of chiral sulfamide-amine alcohols (SAA) (1-6) has been easily synthesized from commercially available chiral amino alcohols. In the absence of Ti(OiPr)4, ligand 4 catalyzed the asymmetric addition of diethylzinc to aromatic aldehydes with moderate to good yields and enantioselectivities.
Mao, Jincheng
experimental part
p. 3710 - 3721
(2009/12/24)

PIPERIDINYL AND PIPERAZINYL MODULATORS OF y-SECRETASE
The present invention relates to compounds of Formula I as shown below, wherein the definitions of Het, R0, R1 R2, R3, R4, R5, R6, R7, R8, and R9 are provided in the specification. Compounds of Formula I are useful for the treatment of diseases associated with γ-secretase activity, including Alzheimer's disease.
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Page/Page column 51

(2009/05/29)

GSM INTERMEDIATES
The present invention relates the use of compounds having the general Formula I, wherein the definitions or R1 and R2 are provided in the specification. Said compounds of Formula I are useful for the synthesis of a variety of g-secretase modulators, which are in turn useful for the treatment of diseases associated with y-secretase activity, including Alzheimer′s disease.
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Page/Page column 130

(2009/05/28)

Catalytic asymmetric alkylation of aldehydes by using trialkylboranes
Triethylborane can be used in the asymmetric alkylation of aldehydes by using a 3-(3,5-diphenylphenyl)-H8-BINOL-derived titanium(IV) catalyst in the presence of an excess amount of titanium tetraisopropoxide. The reaction proceeds with a low catalyst loading (2 mol-%), exhibiting high enantioselectivity for aromatic and unsaturated aldehydes. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Ukon, Takahiro,Harada, Toshiro
scheme or table
p. 4405 - 4407
(2009/05/07)

Synthesis of camphorsulfonamide-based quinoline ligands and their N-oxides: first use in the enantioselective addition of organozinc reagents to aldehydes
The preparation of several camphorsulfonamide-based quinoline derivatives and their N-oxides was accomplished via an indirect Friedlaender synthesis using aminobenzylic alcohols and RuCl2(DMSO)4 as a catalyst. These ligands were tested in the enantioselective addition of dialkylzinc reagents to aldehydes, with enantiomeric excesses up to 96%. A similar protocol using triphenylborane and diethylzinc gave the corresponding phenylation process.
Martinez, Ricardo,Zoli, Luca,Cozzi, Pier Giorgio,Ramon, Diego J.,Yus, Miguel
experimental part
p. 2600 - 2607
(2009/04/11)

1,1′-Binaphthylazepine-based ligands for the enantioselective dialkylzinc addition to aromatic aldehydes
The new 1,1′-binaphthylazepine ligand 1c has been prepared and tested in the enantioselective addition of Et2Zn to arylaldehydes, allowing us to reach ee's up to 97% and giving extremely rapid reactions (10-20 min). Aminoalcohol 1c and the analogous compounds 1a and 1b were then tested in the enantioselective addition of Bu2Zn and Me2Zn to arylaldehydes. All of the ligands efficiently catalyze the Bu2Zn addition to benzaldehyde, providing good yields in short reaction times (2-4 h) and high ee (up to 96%). In the enantioselective methylation of arylaldehydes ligands 1b and 1c gave high yields (88-97%) and good to high (80-90%) ee's.
Pisani, Laura,Superchi, Stefano
p. 1784 - 1789
(2008/12/22)

Fast and enantioselective production of 1-aryl-1-propanols through a single pass, continuous flow process
A functional polymer 4, obtained by reaction of (R)-2-(1-piperazinyl)-1,1, 2-triphenylethanol with a Merrifield resin, has been loaded in a packed bed reactor and used as catalyst for the continuous enantioselective production of 1-arylpropanols by ethyla
Pericas, Miquel A.,Herrerias, Clara I.,Sola, Lluis
scheme or table
p. 927 - 932
(2009/05/07)