A Novel Strategy for the Synthesis of Medium-Sized Lactams (original) (raw)
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Tetrahedron, 2002
AbstractÐAddition of allyl magnesium or metallyl magnesium bromide to the N-benzyl imines of benzaldehyde and cyclohexanone, followed by acylation with acryloyl or metacryloyl chloride provided the corresponding a,b-unsaturated amides. Ring-closing metathesis of the latter with ruthenium catalyst PhCHvRuCl 2 (PPh 3 ) 2 in the presence of Ti(OiPr) 4 provided excellent yields of the corresponding conjugated d-lactams with both disubstituted and trisubstituted CvC bonds. Some speci®c trisubstitution patterns, however, as well as tetrasubstituted CvC bonds, were not obtained. In these cases, even the use of a second generation, imidazolylidene-substituted ruthenium catalyst at high temperature did not lead to success. q
An efficient synthetic route to functionalized δ-lactams
Tetrahedron, 2008
a b s t r a c t This paper describes a convenient synthesis of disubstituted functionalized d-lactams based on Michael addition of primary amines to dimethyl-E-2-alkylidene glutarates 2 followed by an intramolecular cyclisation.
ChemInform Abstract: Advances in Synthesis of Monocyclic β-Lactams
ChemInform, 2015
Recent years have witnessed significant advancement in cycloaddition and cyclization strategies for the synthesis of monocyclic -lactams. Cycloadditions include the Staudinger's keteneimine cycloaddtions and related reaction. Cyclization reactions are reported to furnish -lactams through N1-C2, N1-C4 and C3-C4 bond formations employing substrates like -amino esters, amino alcohols, -hydroxamate esters, and -amino diazocarbonyls, etc. Some other strategies are silyl carbonylation reactions, ring-enlargement of aziridines, cleavage of one ring of a bicyclic -lactam, and functional group transformations on the -lactam rings. Recently, some multi-component reactions have also been designed. This article reviews the advances made in synthetic approaches to monocyclic -lactams during last five years.
β-Lactams: Versatile Building Blocks for the Stereoselective Synthesis of Non-β-Lactam Products
Chemical Reviews, 2007
4465 2.6. Macrocyclic Heterocycles 4468 3. Synthesis of Amino(hydroxy) Acid Derivatives 4474 3.1.-Amino Acids 4474 3.2. R-Hydroxy-amino Acids 4480 3.3. R-Amino Acids 4482 4. Synthesis of-Amino Ketone Derivatives 4484 5. Synthesis of γ-Amino Alcohol Derivatives 4485 6. Miscellaneous 4486 7. Conclusions 4489 8. Abbreviations 4489 9. Acknowledgments 4489 10. References 4489
Bioorganic & Medicinal Chemistry Letters, 2008
We have prepared a novel speculative eight-membered lactam demonstration library based on the skeletal structure of the potent antitumor marine natural product octalactin A. The basic scaffold was readily constructed in a convergent fashion via ring-closing metathesis chemistry from the corresponding diene amides. A cursory examination of the biological properties of the library validates the relevance and significance of these structures.
Advances in synthesis of monocyclic beta-lactams
Arkivoc, 2013
Recent years have witnessed significant advancement in cycloaddition and cyclization strategies for the synthesis of monocyclic β-lactams. Cycloadditions include the Staudinger's keteneimine cycloaddtions and related reaction. Cyclization reactions are reported to furnish β-lactams through N 1-C 2 , N 1-C 4 and C 3-C 4 bond formations employing substrates like β-amino esters, βamino alcohols, β-hydroxamate esters, and α-amino diazocarbonyls, etc. Some other strategies are silyl carbonylation reactions, ring-enlargement of aziridines, cleavage of one ring of a bicyclic β-lactam, and functional group transformations on the β-lactam rings. Recently, some multi-component reactions have also been designed. This article reviews the advances made in synthetic approaches to monocyclic β-lactams during last five years.
Advances in the Catalytic, Asymmetric Synthesis of β-Lactams
Accounts of Chemical Research, 2004
In this Account, we illustrate our contribution to the catalytic, asymmetric synthesis of-lactams through a flexible [2 + 2] cycloaddition strategy. We also explore the scope of our methodology and comment on future directions. Stefan France obtained his B. S. in chemistry from Duke University in 2000 where he studied with Eric Toone. His graduate career began in the fall of 2000 when he joined the research group of Professor Tom Lectka. Stefan's Ph.D. research centers around new methodology for catalytic, asymmetric, and site-selective halogenations. Stefan currently holds fellowships sponsored by the Johns Hopkins University, UNCF, Merck, and Pfizer. Anthony Weatherwax has been awarded several baccalaureate degrees from State University of New York (SUNY), Albany, Arizona, and Maryland. He joined the Lectka group in 2001 and is currently investigating methods for the asymmetric synthesis of-lactams. Andrew E. Taggi obtained his B.S. from Cornell University in 1998. His graduate research with Tom Lectka concerned the development of new methodology for the use of ketenes in catalytic, asymmetric synthesis for which he received an ACS DOC Fellowship, sponsored by Organic Reactions, Inc. A.T. is currently a postdoctoral associate with Professor Jerrold Meinwald (Cornell). Tom Lectka is a native of Detroit who was graduated from Oberlin College in 1986. He obtained his Ph.D from Cornell University, where he worked in John McMurry's laboratory. After a Humboldt Fellowship to study at Heidelberg, he joined Dave Evans's laboratory at Harvard University as a postdoc. In 1994, he began at Johns Hopkins University, where he was promoted to Professor in 2002. His research interests broadly span problems in catalysis and mechanistic organic chemistry.
Biocatalysis for the preparation of optically active β-lactam precursors of amino acids
Tetrahedron: Asymmetry, 1996
Enantioselective acylation of N-hydroxymethylated 13-1actams in the presence of Pseudomonas sp. lipase afforded optically active precursors for the preparation of (1R,2S)-and (1S,2R)-2-aminocyelopentane-and (1R,2S,3R,4S)and (1S,2R,3S,4R)-3-aminobicyclo[2.2.1]heptanecarboxylic acids. Due to the high enantioselectivity (E = 90 and 62) and in order to minimize the enzymatic hydrolysis of the acylated products back to the starting alcohol, the reactions were performed in acetone.