Synthesis of Carbapenam Skeletons Using a Ruthenium-Catalyzed Cyclization

Abstract

Carbapenam is a very important skeleton of beta-lactam antibiotics, and it has a highly strained structure. When enynes 9 were treated with RuH(2)CO(PPh(3))(3) (10 mol %) in toluene upon heating, carbapenams 10 were obtained in good yields.

Cycloisomerization of 1,n‐Enynes: Challenging Metal‐Catalyzed Rearrangements and Mechanistic Insights

“…(44)]. [62] This strategy was applied to the synthesis of highly valuable carbapenam skeletons. The combination of [CpRu(cod)Cl] (cod: cyclo-1,5-diene) and an alcohol such as ethanol can also generate a ruthenium hydride, and therefore lead, for example, to the conversion of 142 into 1,3-diene 142 [Eq.…”

“…Depending on the alkenyl substituent, a classic carbocyclization or a [5+2] cycloaddition was observed and afforded dienes 192 and 194, respectively [Eqs. (62) and (63)]. [79] The asymmetric version of the cycloisomerization reaction of 1,6-enynes was reported by Zhang and co-workers shortly after the racemic version.…”

Ruthenium‐Catalyzed Reactions—A Treasure Trove of Atom‐Economic Transformations

“…[6,205] Some of the more recent applications are detailed in this section. If no b-hydride elimination pathway is available to an enyne, 1,3-dienes can be formed by utilizing ruthenium hydride catalysts, [190,206] in analogy to palladium-catalyzed chemistry. [116] Monosubstituted enyne 283 [Eq.…”

Diastereoselective Syntheses of Functionalized Five-Membered Carbocycles and Heterocycles by a SmI2-Promoted Intramolecular Coupling of Bromoalkynes and α,β-Unsaturated Esters

“…Ethyl {(4Z)-benzylidene-1-toluenesulfonylpyrrolidin-3-yl}acetate (Z-3b). A coupling reaction of phenylacetylene [11] (47.1 mg, 0.1 mmol) using HMPA (0.4 mL), HFIP (63.1 μL, 0.6 mmol) and SmI 2 (0.2 M, THF solution, 2.4 mL, 0.5 mmol) in THF (4.3 mL) was carried out according to the same procedure as described for 2a to yield bromoalkene (Z-3b) (27.9 mg, 59%, E:Z = 12:88) as a colorless oil [eluent: hexane-AcOEt (9 49, 143.75, 138.92, 136.06, 132.50, 129.74 (2), 128.54 (2), 128.05 (2), 127.72 (2), 127. 23, 123.57, 60.71, 52.03, 50.04, 40.92, 37.92, 21.47, 14.14…”