122872-67-7Relevant academic research and scientific papers
Novel Lewis acid-assisted chiral Lewis acid (LLA) system: Development of boroxin-Ti-BINOL-catalyzed asymmetric allylation of aldehydes
Xia, Guoyao,Shibatomi, Kazutaka,Yamamoto, Hisashi
, p. 2437 - 2439 (2004)
The formation of hetero multimetallic complex having B-O-Ti bond could increase the Lewis acidity of titanium. A novel LLA system made up of Ti-BINOL and 4-(trifluoromethyl)phenyl-boroxin dramatically accelerated the allylation reaction of aldehyde with h
3,3′-Bithiophene-Based Chiral Bisphosphine Oxides as Organocatalysts in Silicon-Derived Lewis Acid Mediated Reactions
Benaglia, Maurizio,Benincori, Tiziana,Raimondi, Laura Maria,Rossi, Sergio
, p. 535 - 546 (2020/03/27)
This account summarizes the development of new biheteroaromatic chiral bisphosphine oxides. 3,3′-Bithiophene-based phosphine oxides (BITIOPOs) have been successfully used as organocatalysts to promote Lewis base catalyzed, Lewis acid mediated stereoselective transformations. These highly electron-rich compounds, in combination with trichorosilyl derivatives (allyltrichlorosilane and silicon tetrachloride), generate hypervalent silicon species that act as chiral Lewis acids in highly diastereo- and enantioselective organic reactions. Several relevant examples related to these applications are discussed in detail. 1 Introduction 2 The BITIOPO Family 3 Enantioselective Opening of Epoxides 4 Enantioselective Allylation of Aldehydes 5 Stereoselective Direct (Double) Aldol-Type Reaction with Ketones 6 Stereoselective Direct Aldol-Type Reaction with Ester Derivatives 7 Conclusions.
Bi(cyclopentyl)diol-Derived Boronates in Highly Enantioselective Chiral Phosphoric Acid-Catalyzed Allylation, Propargylation, and Crotylation of Aldehydes
Yuan, Jinping,Jain, Pankaj,Antilla, Jon C.
, p. 12988 - 13003 (2020/11/23)
In this study, we disclose the catalytic addition of bi(cyclopentyl)diol-derived boronates to aldehydes promoted by chiral phosphoric acids, allowing for the formation of enantioenriched homoallylic, propargylic, and crotylic alcohols (up to >99% enantiom
TetraPh-Tol-BITIOPO: A new atropisomeric 3,3′-bithiophene based phosphine oxide as an organocatalyst in Lewis base-catalyzed Lewis acid mediated reactions
Mirco, Abbinante Vincenzo,Maurizio, Benaglia,Sergio, Rossi,Tiziana, Benincori,Roberto, Cirilli,Marco, Pierini
supporting information, p. 7474 - 7481 (2019/08/20)
A new chiral phosphine oxide based on a 3,3′-bithiophene scaffold (TetraPh-Tol-BITIOPO) was synthesized, fully characterized and separated into antipodes through chiral HPLC. This new compound was successfully employed as an organocatalyst in Lewis base-catalyzed Lewis acid mediated reactions involving trichlorosilyl compounds. The new atropisomeric catalyst was able to promote the allylation of aldehydes with allyltrichlorosilane in up to 98% yield and up to 96% enantiomeric excess (ee), and the direct aldol reaction to afford β-hydroxy ketones and β-hydroxy thioesters, with good chemical yields and modest stereochemical efficiency. Computational studies helped to elucidate and to rationalize the stereochemical outcome of the reactions catalyzed by TetraPh-Tol-BITIOPO that was found to favour the formation of the isomer with an opposite absolute configuration in comparison with the products obtained with the previously reported 3,3′-bithiophene-based catalyst.
Axially chiral N,N′-dioxides ethers for catalysis in enantioselective allylation of aldehydes
Wu, Shijie,Xing, Yongfei,Wang, Jie,Guo, Xingchen,Zhu, Huajie,Li, Wan
supporting information, p. 947 - 957 (2019/08/30)
A series of axially chiral ethers synthesized from biscarboline N,N′-dioxides, (S)-1a to (S)-1n, was investigated in enantioselectivity addition reactions of allyltrichlorosilane with a series of substituted aldehydes, including bulky substituted aldehydes. High enantioselectivities (up to 96%ee) were achieved using the catalyst (S)-1k at 1 mol % loading.
Axial-Chiral Biisoquinoline N, N′-Dioxides Bearing Polar Aromatic C-H Bonds as Catalysts in Sakurai-Hosomi-Denmark Allylation
Reep, Carlyn,Morgante, Pierpaolo,Peverati, Roberto,Takenaka, Norito
supporting information, p. 5757 - 5761 (2018/09/29)
The design, synthesis, and evaluation of axial-chiral biisoquinolines bearing polar aromatic C-H bonds as Lewis base catalysts are reported. Lewis bases containing the 3,5-bis(trifluoromethyl)phenyl group were found to be significantly more enantioselecti
Chiral Unsymmetrically Substituted Bipyridine N,N′-Dioxides as Catalysts for the Allylation of Aldehydes
Ul?, Jan,Ne?as, David,Koukal, Petr,Havlí?ek, Vojtěch,To?ner, Zdeněk,Hybelbauerová, Simona,Kotora, Martin
supporting information, p. 5109 - 5116 (2018/07/31)
A series of unsymmetrically substituted diastereoisomeric (Ra,R) and (Sa,R) bipyridine N,N′-dioxides was synthesized by using oxidative coupling of the corresponding metallated tetrahydroisoquinoline N-oxides in the presence of iodin
First total synthesis of the highly potent antitumor lactones 8-chlorogoniodiol and parvistone A: Exploiting a bioinspired late-stage epoxide ring-opening
Ramesh, Perla,Narasimha Reddy, Yarram,Narendar Reddy, Thatikonda,Srinivasu, Navuluri
supporting information, p. 246 - 249 (2017/02/15)
The first protecting group-free total syntheses of the highly potent antitumor chlorinated styryllactone secondary metabolites 8-chlorogoniodiol, parvistone A, and one analogue 8-epi-parvistone A, have been accomplished from commercially available trans-cinnamaldehyde in five steps with high overall yields. The chlorine-bearing stereogenic center of these silent secondary metabolites was introduced via a bioinspired late-stage regioselective epoxide ring-opening strategy. Maruoka asymmetric allylation, acrylation, ring-closing metathesis and asymmetric epoxidation, greatly facilitate the synthesis of the key intermediates goniothalamin oxide and (6S,7S,8S)-isogoniothalamin oxide.
Asymmetric Allylation of Carbonyl Compounds Catalyzed by a Chiral Phosphine–Silver Complex
Yanagisawa, Akira,Yang, Nan,Bamba, Kentaro
supporting information, p. 6614 - 6618 (2017/12/15)
A catalytic, asymmetric allylation reaction of aldehydes or ketones with allyltrimethoxysilane was achieved by using a BINAP·AgBF4 [BINAP = 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl] complex as the chiral precatalyst and triethylamine as the
Enantioselective Allyl-, and Allenylboration of Aldehydes Catalyzed by Chiral Hydroxyl Carboxylic Acid
Ota, Yuya,Kawato, Yuji,Egami, Hiromichi,Hamashima, Yoshitaka
supporting information, p. 976 - 980 (2017/05/05)
Asymmetric allylboration of aldehydes with allylboronic acid pinacol ester catalyzed by chiral hydroxyl carboxylic acid is described. This reaction provides synthetically useful homoallyl alcohols in high yield with good to high enantioselectivity. The pr
