Chemical Synthesis of β-Lactams: Asymmetric Catalysis and Other Recent Advances

The Future of Catalysis by Chiral Lewis Acids

“…Entry into β-lactam structures continues to be of major interest, and methodologies for the asymmetric syntheses of these biologically significant compounds have been reviewed [121]. The synthesis of stable oxetenes by cycloaddition of alkynes with trifluoropyruvates (Scheme 26) that occurs with exceptional enantiocontrol from reactions catalyzed by a dicationic (S)-BINAP-Pd catalyst is a Scheme 23 Asymmetric 1,3-dipolar cycloaddition reaction of nitrile oxides with 3-arylideneoxindoles [102] The Future of Catalysis by Chiral Lewis Acids prime example of the versatility of suitably designed chiral Lewis acids in organic synthesis [122]; catalyst loadings as low as 0.1 mol % were used.…”

A nitrilase-mediated entry to 4-carboxymethyl-β-lactams from chemically prepared 4-(cyanomethyl)azetidin-2-ones

“…[8][9][10][11] In this way, these scaffolds can be deployed in the synthesis of a broad range of new nitrogen compounds with potential bioactivity, which has become a major incentive for the research and development of several new classes of b-lactams. [12][13][14] One of those classes, the family of 4-(cyanomethyl)azetidin-2-ones, contains important synthons for the controlled synthesis of a variety of new compounds including functionalized g-lactams, succinimide derivatives and diamino-b-lactams in optically pure form, all being promising compounds in terms of medicinal and synthetic applications. 15 Besides, the synthesis of multiple antibiotics, with the carbapenem antibiotic thienamycine as one of the most prominent examples, can be dedicated to the use of 4-(cyanomethyl)azetidin-2-one substrates.…”

One-pot conversion of carbamates of unsaturated β-aminoesters into unsaturated β-lactams by use of trimethylsilyl iodide

“…1 The activity of famous antibiotics such as penicillins, cephalosporins and carbapenems are attributed to the presence of the 2-azetidinone ring in these compounds. 2 Apart from clinical use, β-lactams can also serve as good synthons in the synthesis of many biologically active heterocycles.…”

“…2 Apart from clinical use, β-lactams can also serve as good synthons in the synthesis of many biologically active heterocycles. Several approaches have been developed for the synthesis of β-lactams including cyclization of β-aminoesters to α-methylene-β-lactams [3][4][5][6] , Grignard reaction on azetidin-2,3-diones followed by dehydration using PPh 3 /CCl 4 reagent 7 , rhodium catalyzed olefin cross metathesis 8 , thermal β-elimination of trans-3-allyl-3-sulfinyl-β-lactams 9 , copper-catalyzed carbonylative coupling of cycloalkanes and amides 10 , synthesis of optically active α-methylene β-lactams through lipase-catalyzed kinetic resolution 11 , synthesis of optically active spiro-β-lactams by cycloadditions to α-alkylidene-β-lactams 12 and other miscellaneous approaches such as ring contraction and radical processes 1 . Recently Li and co-workers described the palladiumcatalyzed direct oxidative carbonylation of N-allylamines palladium 13 and PPh 3 -catalyzed umpolung cyclization of 2-propiolamidoacetates or α-propiolamido ketones 14 .…”