Ruthenium-Catalyzed Alkenylative Cyclization via Insertion of Alkene into Ruthenacyclopentene

Abstract

S2General. Toluene was distilled under an argon atmosphere from Na/benzophenone. All the solvents using the organometallic agents were degassed through a freeze-pump-thaw cycle. Ethylene gas was purified by passing through the aqueous CuCl solution (2g of CuCl in 180 mL of saturated aqueous NH 4 Cl), concentrated H 2 SO 4 , and a KOH drying tube. Synthesis of substrates4,4-Bis(benzyloxymethyl)-hept-1-en-6-yne-7-d (1c-D). BnO BnO 2. D 2 O BnO BnO D 1c 1c-D; 77%

Ynamides: Versatile Tools in Organic Synthesis

“…Cyclic amido‐dienes such as 138 and 140 were shown to be excellent partners in Diels–Alder reactions. Replacement of the Grubbs catalyst by another ruthenium complex, [Cp*RuCl(cod)], allows for a completely different reaction, since an alkenylative cyclization occurs in this case 89…”

Ynamides: A Modern Functional Group for the New Millennium

“…Six years later147, they revisited this issue and by exploring the use of other ruthenium catalysts, they were able to optimize the yields of 1-azadienes such as 593 from ene-ynamide 589 . They proposed that the mechanism for these transformations occurs through ruthenacyclopentene 590 into which ethylene can undergo olefin insertion to give ruthenacycloheptene 591 .…”

Transition‐Metal‐Catalyzed Laboratory‐Scale Carbon–Carbon Bond‐Forming Reactions of Ethylene

“…[67] The authors attributed the formation of 97 to an initial ruthenacyclization to form the ruthenacyclopentene 98 with subsequent ethylene insertion to form the ruthenacycloheptene 99 . Subsequent β-hydride elimination could afford the ruthenium hydride 100 , which could reductively eliminate to give the exocyclic diene 97 .…”

“…[67] The use of 5 mol% of non-alkylidenyl [Cp*RuCl(cod)] significantly enhanced the yield of the exocyclic diene 107 at room temperature within 3 hours. In fact, none of the metathesis product 108 was observed.…”