Towards a General Synthesis of 3‐Metal‐Substituted β‐Lactams

Abstract

Joining metals and antibiotics: Studies towards a general method for the synthesis of β-lactams that have a metal complex moiety attached to the C3-position are reported (see scheme). The cis/trans selectivity of the reactions ranges from low in complexes containing the alkyne moiety joined directly to the cyclopentadienyl ring to complete when the metal moiety is separated from the reactive alkyne by an alkynyl-aryl fragment.

Stereoisomeric products of electrochemical reduction of heterocyclic Fischer aminocarbene Cr(0) complexes. Development of the electrochemistry-mass spectrometry tandem approach using biphasic (acetonitrile-hexane) preparative electrolysis

“…In the frame of systematic electrochemical investigation of Fischer aminocarbene complexes, namely their reducibility and reactivity, preparative electrolyses have been performed on a series of newly synthesized [19] aminocarbene complexes bearing various five-membered heteroaromatic (furan, thiophene, Nmethylpyrrole) rings attached by position 2 or 3 in acetonitrile.…”

“…Currently, besides our previous works [20][21][22][23][24] only several papers are concerned with the electrochemistry of aminocarbene complexes of various metals [13,[25][26][27][28][29], which are focussed mainly to the first reduction (oxidation) step and to the comparison with the alkoxycarbenes. Further steps following the electron transfer including the electrolysis products are, however, not discussed.…”

“…Much less articles deal with thermal reactivity and characteristics (including ESI-MS [14,15]) of Fischer type aminocarbene complexes [2,4,5,[16][17][18][19] which are generally more stable against reduction than the alkoxy derivatives.…”

Copper(I)‐Catalyzed Asymmetric Interrupted Kinugasa Reaction: Synthesis of α‐Thiofunctional Chiral β‐Lactams

“…In 1995, the first catalytic reaction of terminal alkynes and nitrones was developd by Miura et al [9b] . Recently, the asymmetric catalytic Kinugasa reaction was realized by the Fu group and others, and provides a catalytic enantioselective synthesis of β‐lactams from readily available starting materials [9c–j] . However these reactions can only produce a 3,4‐disubstituted product ( K ).…”

Kinugasa reaction: an ‘ugly duckling’ of β-lactam chemistry

“…Selection of optimal reaction conditions led to identification of s-Bu 2 NH as the best amine and i-PrOAc as the best solvent. Very recently, Sierra et al 89 applied ligand 105c ina synthesis of β-lactams starting from terminal alkynes substituted with metal fragments, including sandwich, half-sandwich and arene-tethered metal-carbene complexes, but the enantioselectivity of the process was rather low (<35% ee).…”