Sc(OTf)3-Catalyzed Cyclization of Allyl Amides of Ethenetricarboxylate

Abstract

Catalytic cyclization of allyl amides of ethenetricarboxylate leading to pyrrolidines has been examined. Reaction of allyl amides of ethenetricarboxylate with Sc(OTf) 3 (0.2 equiv) gave 4-hydroxymethyl-2-oxopyrrolidine derivatives as major products. The formation of hydroxymethylpyrrolidines may arise from participation of adventitious water in situ. Sc(OTf) 3-catalyzed cyclization reactions of the allyl amides with TMSX (X = Cl, Br) proceeded efficiently to give halogenated 2-oxopyrrolidine derivatives. Sc(OTf) 3-catalyzed cyclization reactions of the allyl ester with TMSX (X= Cl, Br) also proceeded to give halogenated 2oxotetrahydrofuran derivatives.

Intramolecular cyclization reactions of arylpropargyl amides of electron-deficient α,β-alkenyl carboxylates and related compounds

“…A similar type of cyclization/water addition was previously observed in the Sc(OTf) 3 -catalyzed reaction of allyl amides of ethenetricarboxylate in 1,2-dichloroethane. 13…”

“…A similar type of cyclization/water addition was previously observed in the Sc(OTf ) 3catalyzed reaction of allyl amides of ethenetricarboxylate in 1,2-dichloroethane. 13 Next, the reaction of 4,4,4-trifluoro-2-butenamide 3m was examined (Scheme 8). The reaction of 3m with DBU in xylene at 140 °C or in toluene at 110 °C gave a complex mixture and the cycloadducts could not be isolated.…”

Catalytic Cycloisomerization of Enyne Diesters Derived From 2‐Propargyloxyarylaldehydes

“…[1][2][3][4][5][6] The requisites of this type of cyclization are an electrophilic alkene (such as diethyl 2-arylidene malonate) bearing coordination site for metal halides and an alkyne which acts as the nucleophile. While the analogous ene-ene cyclization [7][8][9][10][11][12][13][14][15][16] is facile, enyne cyclization is less facile due to low nucleophilicity of alkyne and thus often requires highly electrophilic olefin containing three electron-withdrawing groups. Snider et al showed that in the presence of stoichiometric amount metal halide containing nucleophilic ligand such as FeCl 3 , enyne triester of type 1 undergoes intramolecular cyclization to compound 2 (Scheme 1a).…”

“…The requisites of this type of cyclization are an electrophilic alkene (such as diethyl 2‐arylidene malonate) bearing coordination site for metal halides and an alkyne which acts as the nucleophile. While the analogous ene‐ene cyclization [7–16] is facile, enyne cyclization is less facile due to low nucleophilicity of alkyne and thus often requires highly electrophilic olefin containing three electron‐withdrawing groups. Snider et al.…”

α,γ-Dioxygenated amides via tandem Brook rearrangement/radical oxygenation reactions and their application to syntheses of γ-lactams

“…Various synthetic pathways can be applied for the construction of the γ-lactam scaffold [40][41][42][43][44]. The pyrrolidinone fragment is often synthesized by transition metal- [45][46][47][48][49][50] or Lewis acidcatalyzed cyclization reactions [51][52][53][54]. The Diels-Alder reaction can also be used for the preparation of functionalized γ-lactams in a single step [55].…”