Pt-catalyzed cyclization/migration of propargylic alcohols for the synthesis of 3(2H)-furanones, pyrrolones, indolizines, and indolizinones

Abstract

Several heterocycles such as furanones, pyrrolones, and indolizines, which are of pharmacological importance, are easily accessed via the Pt(II)-catalyzed heterocyclization/1,2-migration of propargylic ketols or hydroxy imine derivatives. This method sidesteps the challenges of traditional heteroaromatic oxygenation strategies such as regioselectivity and functional group tolerance in the syntheses of these heterocycles.

A facile base-promoted domino Michael/O-alkylation reaction for the construction of succinimide-substituted 3(2H)-furanones

“…Under the optimal reaction conditions, the generality of this protocol was studied (Table 3). Firstly, a wide range of maleimides 1a-n was studied (Table 3, entries [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The maleimides included those bearing electronwithdrawing and electron-donating substituents on the aryl ring, as well as N-alkyl maleimides.…”

“…[1][2][3][4] The significance of these molecules has led to a variety of approaches for the synthesis of substituted 3(2H)-furanones, including acid-catalyzed cyclization-dehydration, 5,6 transformations from furans, 7,8 alkynes [9][10][11][12][13][14][15] and allenes. 16 However, most of these routes require the use of specific substrates and reaction conditions are often harsh.…”

Transition Metal‐Catalyzed Synthesis of Fused Five‐Membered Aromatic Heterocycles

“…It should be noted that a variety of transition metals, such as Au(I), Au(III), Cu(I), Pt(II), and Pd(II), were shown to catalyze this transformation with variable degrees of efficiency. Very recently, the Pt(II)-catalyzed version of an analogous cycloisomerization of skipped propargylpyridines 351 into N-fused heterocycles 352 was reported by Sarpong (Scheme 9.123) [302,303].…”

Indolizinones as synthetic scaffolds: fundamental reactivity and the relay of stereochemical information

“…Methods for the synthesis of indolizinones were pioneered in our laboratories with platinum(II) and indium(III) salts 1,3 and have been further developed by others with salts or complexes of copper, 2 silver, 6 gold 6 and iodine. 4 This transformation is proposed to proceed by cyclization of the pyridine moiety (see 2 , Fig.…”