Asymmetric Vinylogous Mannich Reaction Research Articles

ChemInform Abstract: Recent Advances in Metal‐Catalyzed Asymmetric Mannich Reactions

AbstractReview: 122 refs.

ChemInform Abstract: Cinchona Alkaloid Amide/Copper(II) Catalyzed Diastereo‐ and Enantioselective Vinylogous Mannich Reaction of Ketimines with Siloxyfurans.

AbstractThe asymmetric vinylogous Mannich reaction of unactivated ketimines with siloxyfurans using cinchona alkaloids and Cu(OAc)2 as catalysts is reported.

Recent Advances in Metal-Catalyzed Asymmetric Mannich Reactions

In this review, recent works on metal-catalyzed asymmetric Mannich, aza-Henry and vinylogous Mannich reactions are described. The asymmetric Mannich reaction is one of the most powerful methodologies among the carbon–carbon bond-forming reactions, and provides direct access to a wide range of optically active natural products with useful biological properties. 1 Introduction 2 Catalytic Asymmetric Mannich Reactions 2.1 BINOL Ligands 2.2 BINAP Ligands 2.3 Bisoxazoline Ligands 2.4 Pyridine Bisoxazoline Ligands 2.5 Diamine Ligands 2.6 P,N-Ligands 2.7 P,S-Ligands 2.8 P,P-Ligands 2.9 N,N-Ligands 2.10 Miscellaneous 3 Asymmetric Aza-Henry Reactions 3.1 BINOL Ligands 3.2 Bisoxazoline Ligands 3.3 N,N-Ligands 3.4 Miscellaneous 4 Asymmetric Vinylogous Mannich Reactions 5 Conclusion

New silver(I)–monophosphine complex derived from chiral Ar-BINMOL: synthesis and catalytic activity in asymmetric vinylogous Mannich reaction

A new family of C2-axially chiral monophosphines (Ar-NNPs) from Ar-BINMOLs was developed for silver-catalyzed asymmetric vinylogous Mannich reaction of (furan-2-yloxy)trimethylsilane with aromatic aldimines. It was found that the enantioselective vinylogous Mannich-type reactions of trimethylsiloxyfuran with aldimines are catalyzed efficiently by silver(I) complexes of the Ar-BINMOL-derived chiral monophosphine. This procedure displays wide aldimine versatility, excellent yields (up to 99% isolated yields), moderate to good enantioselectivity (up to 78%ee) and exceptional diastereoselectivity (>99:1 dr) in most cases examined. The molecular structure of silver–monophosphine complex was confirmed by X-ray analysis and revealed that the benzyl group on chiral monophosphine provided dual function with weak silver–π/π–π stacking and steric repulsion to favour the diastereoselective Re-nucleophilic addition of siloxyfuran to imine.

Cinchona Alkaloid Amide/Copper(II) Catalyzed Diastereo‐ and Enantioselective Vinylogous Mannich Reaction of Ketimines with Siloxyfurans

The asymmetric vinylogous Mannich reaction of unactivated ketimines with siloxyfurans using cinchona alkaloids and Cu(OAc)2 as catalysts is reported.

ChemInform Abstract: Direct Asymmetric Vinylogous Mannich Reaction of 3,4‐Dihalofuran‐2(5H)‐one with Aldimine Catalyzed by Quinine.

AbstractFuranones of type (III) are useful synthons which can be converted into optically active butyrolactones such as (IV) and amino diols like (V).

Direct Asymmetric Vinylogous Mannich Reaction of 3,4-Dihalofuran-2(5H)-one with Aldimine Catalyzed by Quinine

The direct asymmetric vinylogous Mannich reaction of 3,4-dihalofuran-2(5H)-one with aldimine catalyzed by quinine was first reported, and γ-butenolides have been obtained in excellent yield (up to 98%) and enantioselectivities (up to 95% ee). The synthetic applications of this protocol are demonstrated in the preparations of γ-substituted amino butyrolactones and vicinal amino alcohols.

Asymmetric Vinylogous Mannich Reactions: A Versatile Approach to Functionalized Heterocycles

Asymmetric vinylogous Mannich reaction (VMR) of 2-(tert-butyldimethylsilyloxy)furan (TBSOF, 1) with (R(S))- or (S(S))-t-BS-imines (3) furnished 5-aminoalkylbutenolides 7a-k in 75-87% yields with anti/syn ratios ranging from 75:25 to 97:3. Butenolides 7a-f,k were readily converted into substituted lactones 8 and 5 and 6-substituted 5-hydroxypiperidin-2-ones 11a-g, which are, in turn, key intermediates for the synthesis of many bioactive compounds.

ChemInform Abstract: Highly Diastereo‐ and Enantioselective Vinylogous Mannich Reactions of Fluorinated Aldimines with Siloxyfurans.

A highly regio- and enantioselective asymmetric vinylogous Mannich reaction of readily available fluorinated aldimines bearing a chiral auxiliary [(S)-1-phenylethyl group] with siloxyfurans to afford chiral fluorine-containing γ-butenolide or γ-lactone derivatives has been developed in the presence of silver acetate (10 mol%) and axially chiral phosphine-oxazoline ligand L1 (11 mol%). In most cases, the corresponding fluorinated adducts were obtained in high yields, good to excellent enantiomeric excesses and up to > 20:1 dr.

ChemInform Abstract: Highly Efficient Asymmetric Vinylogous Mannich Reaction Induced by O‐Pivaloylated D‐Galactosylamine as the Chiral Auxiliary.

AbstractA new and efficient asymmetric access to a number of γ‐butenolide derivatives is presented.

Highly Diastereo‐ and Enantioselective Vinylogous Mannich Reactions of Fluorinated Aldimines with Siloxyfurans

AbstractA highly regio‐ and enantioselective asymmetric vinylogous Mannich reaction of readily available fluorinated aldimines bearing a chiral auxiliary [(S)‐1‐phenylethyl group] with siloxyfurans to afford chiral fluorine‐containing γ‐butenolide or γ‐lactone derivatives has been developed in the presence of silver acetate (10 mol%) and axially chiral phosphine‐oxazoline ligand L1 (11 mol%). In most cases, the corresponding fluorinated adducts were obtained in high yields, good to excellent enantiomeric excesses and up to>20:1 dr.

Highly efficient asymmetric vinylogous Mannich reaction induced by O-pivaloylated d-galactosylamine as the chiral auxiliary

The diastereospecific formation of β-N-glycoside-linked α-amino-2(5H)-furanone has been achieved with high yield via a vinylogous Mannich reaction. The reaction was performed by using O-pivaloylated galactosylamine 1 as a chiral template and ZnCl(2)·Et(2)O as a promoter in Et(2)O. Imines 3 of aromatic compounds and trimethylsiloxyfuran 4 were converted to N-galactosyl α-amino-2(5H)-furanone 5, giving ratios of diastereomers higher than 20:1. This procedure provides rapid access to biologically important γ-butenolide derivatives.

Highly Diastereoselective Three-Component Vinylogous Mannich Reaction between Isoquinolines, Acyl/Sulfonyl Chlorides, and Silyloxyfurans

Reaction of an isoquinoline, a silyloxyfuran, and an acyl or sulfonyl chloride provides easy access to a wide variety of isoquinolinobutyrolactones with excellent yields and diastereoselectivites (R*,R* isomer), even in the case of formation of quaternary centers (i.e., R(3) or R(4) = Me). Moreover, the use of a chiral auxiliary allowed formation of a single stereoisomer in 96% yield. This represents the first examples of asymmetric vinylogous Mannich reactions on isoquinolinium salts.

The application of chiral phosphine-Schiff base type ligands in silver(I)-catalyzed asymmetric vinylogous Mannich reaction of aldimines with trimethylsiloxyfuran

Catalytic asymmetric vinylogous Mannich (AVM) reactions of readily available aldimines with trimethylsiloxyfuran in the presence of catalytic amount of AgOAc and chiral phosphine-Schiff base type ligands are described, affording the corresponding products in up to 91% yield, anti/ syn >99:1 and 81% ee.

Catalytic Asymmetric Vinylogous Mannich Reaction of N-(2-Thienyl)sulfonylimines

Both cyclic and acyclic silyl dienol ethers participate efficiently in the asymmetric vinylogous Mannich reaction of N-2-thienylsulfonylimines catalyzed by copper(I) complexes of Fesulphos ligands. This procedure displays wide imine and nucleophile versatility, high enantiocontrol, and complete gamma-regioselectivity in most cases examined. The mild sulfonamide deprotection allows the resulting products to be readily transformed into optically active delta-lactams or 5-hydroxy-2-piperidone derivatives.

The Asymmetric Vinylogous Mannich Reaction of Dicyanoalkylidenes with α‐Amido Sulfones under Phase‐Transfer Conditions.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

A Highly Efficient and Practical Method for Catalytic Asymmetric Vinylogous Mannich (AVM) Reactions.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Organocatalytic and Highly Stereoselective Direct Vinylogous Mannich Reaction

The first direct asymmetric vinylogous Mannich (AVM) reaction of alpha,alpha-dicyanoolefins and N-Boc aldimines was described promoted by a simple chiral bifunctional thiourea-tertairy amine organocatalyst. The reaction was highly efficient (S/C up to 1000) and regio-, stereoselective (generally >99% de, 96 to >99.5% ee) at room temperature for a broad array of substrates. Enantiomerically pure delta-amino acid could be smoothly prepared from the adduct.

The asymmetric vinylogous Mannich reaction of dicyanoalkylidenes with α-amido sulfones under phase-transfer conditions

The stereoselective vinylogous Mannich reaction of dicyanoalkylidenes under phase-transfer catalytic conditions utilizing stable alpha-amido sulfones as imine precursors is presented; a rigid pyrrolidinium salt acts as the phase-transfer catalyst, giving access to the amino alkylated products in generally good yield and up to 95% ee.

A Highly Efficient and Practical Method for Catalytic Asymmetric Vinylogous Mannich (AVM) Reactions

Very selective but very easy: These are two of the attributes of the asymmetric vinylogous Mannich reactions presented herein. These reactions can be run on a gram scale and in undistilled THF and air (see scheme; TMS=SiMe3). All that is needed is commercially available AgOAc, a readily available amino acid derived phosphine, and a commercially available or easily prepared (one step) siloxyfuran. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z603496_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.