Methods of Organic Chemistry. (Houben-Weyl). Additional and Supplementary Volumes to the 4th Edition. Stereoselective Synthesis. Volume E21a. Nomenclature, Principles, Analytic, Axially Chiral Compounds, Bond Disconnection, Alkylation Reactions, and Insertion into C−H Bonds. Volume E21b. C−C Bond Formation by Addition to O, N, −−X, −O, −N, −NX, and −SX. Volume E21c. C−C Bond Formation by Addition to CC, Cycloaddition Reactions, and Ene Reaction. Volume E21d. C−C Bond Formation by Sigmatropic Rearrangements, Electrocyclic Reactions, C−H, and C−Hal Bond Formation. Volume E21e. Bond Formation:  C−N, C−O, C−P, C−S, C−Se, C−Si, C−Sn, and C−Te. Volume E21f. Survey of Chiral Auxiliaries, Solvents, Reagents, and Catalysts Edited by Gunter Helmchen, Reinhard W. Hoffmann, Johann Mulzer, and Ernst Schumann. Georg Thieme Verlag, Stuttgart, Germany. Volume E21a:  1995. xix + 1168 pp. 17.5 × 25.5 cm. ISBN 3-13-219504-9. DM 2840.00. Volume E21b:  1995. xviii + 1051 pp. 17.5 × 25.5 cm. ISBN 3-13-219504-9. DM 2480.00. Volume E21c:  1995. xv + 1096 pp. 17.5 × 25.5 cm. ISBN 3-13-798004-6. DM 2550.00. Volume E21d:  1995. xiv + 1020 pp. 17.5 × 25.5 cm. ISBN 3-13-100114-3. DM 2770. Volume E21e:  1995. xxi + 1261 pp. 17.5 × 25.5 cm. ISBN 3-13-100124-0. DM 2980.00. Volume E21f:  1996. xlii + 1230 pp. 17.5 × 25.5 cm. ISBN 3-13-102794-0. DM 1930.00. Volume Set:  approximately DM 13900.00.Workbench Edition(10 Volume Set). ISBN 3-13-106124-3. DM 3600.

1996 ◽  
Vol 39 (25) ◽  
pp. 5026-5026
Keyword(s):  
Stereoselective Synthesis ◽  
Bond Formation ◽  
Chiral Auxiliaries ◽  
Reaction Volume ◽  
Ene Reaction ◽  
Chiral Compounds ◽  
Electrocyclic Reactions ◽  
Sigmatropic Rearrangements ◽  
Axially Chiral ◽  
Alkylation Reactions

Ephedrines as Chiral Auxiliaries in Enantioselective Alkylation Reactions of Acyl Ephedrine Amides and Esters: A Review

2018 ◽  
Vol 15 (1) ◽  
pp. 38-83 ◽  
Author(s):  
Alejandro Cruz ◽  
Itzia I. Padilla-Martínez ◽  
Maria E. Bautista-Ramirez
Keyword(s):  
Asymmetric Synthesis ◽  
Bond Formation ◽  
Alkyl Halides ◽  
Aldol Reactions ◽  
Alkylation Reaction ◽  
Chiral Auxiliaries ◽  
Asymmetric Alkylation ◽  
Chiral Compounds ◽  
High Yields ◽  
Alkylation Reactions

Background: In modern chemistry, the asymmetric synthesis for the preparation of high purity chiral compounds to be used as pharmaceuticals or additives in foods have been of capital importance. Chiral auxiliary reagents are used to control the stereochemistry of the reaction in the generation of new chiral compounds, in this context, Ephedra compounds (ephedrines and pseudoephedrines) and some of their derivatives have been broadly used as chiral ligands in catalysis or chiral inductors in asymmetric synthesis. Objective: This review focuses on recent progress in the use of ephedra compounds and their N-substituted derivatives as chiral auxiliaries in the area of asymmetric synthesis, via the alkylation reaction of the enolates derived from their corresponding N-Acyl or O-Acyl derivatives, in the C-C bond formation. Conclusion: A vast amount of work has been done about the use of ephedra compounds in asymmetric synthesis area, in general, it was found that pseudoephedrines are much more effective than ephedrines and are preferred as chiral auxiliaries in the asymmetric alkylation of the corresponding N-acyl amides or O-Acyl esters. Alkylation with alkyl halides requires the use of more than 4 equivalents of LiCl to accelerate the alkylation rate and to complete the reaction without effecting the diastereoselectivity of the process. In contrast, the use of secondary alkyl halides was found to make the reaction very slow. Furthermore, a lot of work about the alkylation reaction in the opening of epoxides and aziridines, aldolic condensation, Manich reaction, addition of nucleophiles to α,β-unsaturated ephedrine amides and Michael additions have been demonstrated to be effective in the C-C bond formation. The aldol reaction of chiral enolates, proceeds with decreasing yields and enantioselectivities as the steric demand of the α-R of ephedrine amides and the size of carbonyl compound increase. In addition, the use of branched groups on N,N-disubstituted norephedrine esters is highly recommended in the aldol reactions of aromatic and aliphatic aldehydes.In the case of N-Acyl or O-Acyl ephedrines supported on polymers, the reaction proceed with good enantioselectivities but low yields, the enantioselectivities are goods but the yields are low. In general, the removal step of the auxiliary proceeds with low to high yields but without epimerization.

scholarly journals Towards Atropoenantiopure N–C Axially Chiral Compounds via Stereoselective C–N Bond Formation

2020 ◽  
Vol 74 (11) ◽  
pp. 883-889
Author(s):  
Johanna Frey ◽  
Sabine Choppin ◽  
Françoise Colobert ◽  
Joanna Wencel-Delord
Keyword(s):  
Medicinal Chemistry ◽  
Bond Formation ◽  
Bond Forming ◽  
Chiral Compounds ◽  
Axially Chiral ◽  
Pure Compounds ◽  
Synthetic Routes ◽  
Metal Catalyzed ◽  
Synthetic Approaches ◽  
Optically Pure

N–C axial chirality, although disregarded for decades, is an interesting type of chirality with appealing applications in medicinal chemistry and agrochemistry. However, atroposelective synthesis of optically pure compounds is extremely challenging and only a limited number of synthetic routes have been designed. In particular, asymmetric N-arylation reactions allowing atroposelective N–C bond forming events remain scarce, although great advances have been achieved recently. In this minireview we summarize the synthetic approaches towards synthesis of N–C axially chiral compounds via stereocontrolled N–C bond forming events. Both organo-catalyzed and metal-catalyzed transformations are described, thus illustrating the diversity and specificity of both strategies.

Synthesis of Axially Chiral 2,2’-Bisphosphobiarenes via a Nickel-Catalyzed Asymmetric Ullmann Coupling: General Access to Privileged Chiral Ligands without Optical Resolution

2020 ◽  
Author(s):  
Ziqing Zuo ◽  
Raphael Kim ◽  
Donald Watson
Keyword(s):  
Optical Resolution ◽  
Chiral Ligands ◽  
Chiral Auxiliaries ◽  
Axially Chiral ◽  
Ullmann Coupling

<div><p>We report an asymmetric Ullmann-type homocoupling of <i>ortho-</i>(iodo)arylphosphine oxides and <i>ortho</i>-(iodo)arylphosphonates that results in highly enantioenriched axially chiral bisphosphine oxides and bisphosphonates in good yields and excellent enantioselectivities. These products are readily converted to enantioenriched biaryl bisphosphines without need for chiral auxiliaries or optical resolution. This process provides a straightforward and practical route for the development of previously uninvestigated atroposelective biaryl bisphosphine ligands.</p></div>

Directed Ortho-Lithiation of Aminophosphazenes: An Efficient Route to the Stereoselective Synthesis of P-Chiral Compounds

2013 ◽  
Vol 15 (10) ◽  
pp. 2378-2381 ◽  
Author(s):  
María Casimiro ◽  
Laura Roces ◽  
Santiago García-Granda ◽  
María José Iglesias ◽  
Fernando López Ortiz
Keyword(s):  
Stereoselective Synthesis ◽  
Chiral Compounds ◽  
Efficient Route

Recent advances and new concepts for the synthesis of axially stereoenriched biaryls

2015 ◽  
Vol 44 (11) ◽  
pp. 3418-3430 ◽  
Author(s):  
J. Wencel-Delord ◽  
A. Panossian ◽  
F. R. Leroux ◽  
F. Colobert
Keyword(s):  
Chiral Compounds ◽  
The Past ◽  
Recent Advances ◽  
New Concepts ◽  
Axially Chiral ◽  
Recent Developments ◽  
Synthetic Routes

Over the past decade the field of the synthesis of axially chiral compounds has been rapidly expanding. Not only key advances have been achieved concerning the already established strategies but also new synthetic routes have been devised. This review showcases the recent developments in this domain.

Ruthenium-Catalyzed Carbon−Carbon Bond Formation between Propargylic Alcohols and Alkenes via the Allenylidene-Ene Reaction

2003 ◽  
Vol 125 (20) ◽  
pp. 6060-6061 ◽  
Author(s):  
Yoshiaki Nishibayashi ◽  
Youichi Inada ◽  
Masanobu Hidai ◽  
Sakae Uemura
Keyword(s):  
Bond Formation ◽  
Carbon Bond ◽  
Ene Reaction ◽  
Propargylic Alcohols ◽  
Carbon Carbon Bond

scholarly journals Double Asymmetric Alkylation Reactions Using C2-symmetric Benzene Based Bis(2-amino-2-oxazolines) Chiral Auxiliaries

2011 ◽  
Vol 32 (11) ◽  
pp. 4133-4136 ◽  
Author(s):  
Song-Yi Jeong ◽  
Quynh Pham Bao Nguyen ◽  
Hyung-Jin Kim ◽  
Taek-Hyeon Kim
Keyword(s):  
Chiral Auxiliaries ◽  
Asymmetric Alkylation ◽  
Alkylation Reactions

scholarly journals Carbohydrates and Terpenes as Chiral Auxiliaries: the Stereoselective Synthesis of (+) or (-)-β-Piperonyl-γ-Butirolactone

1996 ◽  
Vol 7 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Paulo R.R. Costa ◽  
Vitor Francisco Ferreira ◽  
Hiram C. A. Filho ◽  
Sergio Pinheiro
Keyword(s):  
Stereoselective Synthesis ◽  
Chiral Auxiliaries

scholarly journals Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

2021 ◽  
Vol 17 ◽  
pp. 2729-2764
Author(s):  
Alemayehu Gashaw Woldegiorgis ◽  
Xufeng Lin
Keyword(s):  
Phosphoric Acid ◽  
Asymmetric Catalysis ◽  
Medicinal Chemistry ◽  
High Efficiency ◽  
Biologically Active ◽  
Chiral Compounds ◽  
Chiral Phosphoric Acid ◽  
Wide Range ◽  
Axially Chiral ◽  
Acid Catalyzed

In recent years, the synthesis of axially chiral compounds has received considerable attention due to their extensive application as biologically active compounds in medicinal chemistry and as chiral ligands in asymmetric catalysis. Chiral phosphoric acids are recognized as efficient organocatalysts for a variety of enantioselective transformations. In this review, we summarize the recent development of chiral phosphoric acid-catalyzed synthesis of a wide range of axially chiral biaryls, heterobiaryls, vinylarenes, N-arylamines, spiranes, and allenes with high efficiency and excellent stereoselectivity.

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