Synergistic Rh(II)- and Zn(II)-Catalyzed [3 + 3] Annulation of Diazoenals and α-Hydroxy Ketones for the Direct Synthesis of 2H-Pyrans, A Gateway Toward γ-Pyrones DOI
Pratap Kumar Mandal, Sreenivas Katukojvala

Organic Letters, Год журнала: 2024, Номер 26(43), С. 9227 - 9232

Опубликована: Окт. 21, 2024

A new synergistic Rh(II)/Zn(II)-catalyzed [3 + 3] annulation has been developed between diazoenals and α-hydroxy ketones enabling the direct synthesis of 4-formyl-2H-pyrans. The reaction involves formation protic oxonium ylides from highly electrophilic Rh-enalcarbenoids followed by Zn-templated regioselective intramolecular aldol condensation. Subsequent investigations demonstrated that 4-formyl-2H-pyrans are unique precursors γ-pyrones. γ-pyrones were obtained via Et3N-mediated oxidative deformylation. Further, triflic-acid-promoted double Schmidt provides synthetically important carboxamide-substituted 4-cyano 2H-pyrans.

Язык: Английский

Site‐Selective Direct γ‐Difunctionalization of Diazoenals: Application to the Synthesis of Enal‐Functionalized Allenes and Furans DOI Open Access
Jagadeesh Kalepu, Bapurao Sudam Lad, Pratap Kumar Mandal

и другие.

Chemistry - An Asian Journal, Год журнала: 2024, Номер unknown

Опубликована: Окт. 23, 2024

A new approach for the synthetically important γ-functionalized enals has been developed. The strategy involves rhodium-catalyzed direct C-C & C-S bond forming site-selective γ-difunctionalization of diazoenals with aryl propargyl sulfides via sulfur ylide [2,3] sigmatropic rearrangement, resulting in highly functionalized γ-allenyl(sulfanyl)enals excellent yield at ambient temperature. This versatile constitutes a viable alternative to remote carbonyl-directed γ-functionalization unmodified which suffer from competitive side reactions. synthetic utility was demonstrated by InCl

Язык: Английский

Процитировано

1

Copper-enalcarbenoids: Rapid access to 1,7-disubstituted indoles via [4+2] benzannulation between diazoenals and N-substituted pyrroles DOI
Bapurao Sudam Lad, Pratap Kumar Mandal,

Rahul Chakrawarti

и другие.

Tetrahedron Letters, Год журнала: 2024, Номер unknown, С. 155331 - 155331

Опубликована: Окт. 1, 2024

Язык: Английский

Процитировано

0

Synergistic Rh(II)- and Zn(II)-Catalyzed [3 + 3] Annulation of Diazoenals and α-Hydroxy Ketones for the Direct Synthesis of 2H-Pyrans, A Gateway Toward γ-Pyrones DOI
Pratap Kumar Mandal, Sreenivas Katukojvala

Organic Letters, Год журнала: 2024, Номер 26(43), С. 9227 - 9232

Опубликована: Окт. 21, 2024

A new synergistic Rh(II)/Zn(II)-catalyzed [3 + 3] annulation has been developed between diazoenals and α-hydroxy ketones enabling the direct synthesis of 4-formyl-2H-pyrans. The reaction involves formation protic oxonium ylides from highly electrophilic Rh-enalcarbenoids followed by Zn-templated regioselective intramolecular aldol condensation. Subsequent investigations demonstrated that 4-formyl-2H-pyrans are unique precursors γ-pyrones. γ-pyrones were obtained via Et3N-mediated oxidative deformylation. Further, triflic-acid-promoted double Schmidt provides synthetically important carboxamide-substituted 4-cyano 2H-pyrans.

Язык: Английский

Процитировано

0