Silver‐Catalyzed One‐Pot Cyclization Reaction of Electron‐ Deficient Alkynes and 2‐Yn‐1‐ols: An Efficient Domino Process to Polysubstituted Furans

Abstract

Transition metal-catalyzed domino reactions have been used as powerful tools for the preparation of polysubstituted furans in a one-pot manner. In this paper, an efficient synthetic method was developed for the construction of tri-or tetrasubstituted furans from electron-deficient alkynes and 2-yn-1-ols by a silver-catalyzed domino reaction. It is especially noteworthy that a 2,3,5-trisubstituted 4-ynylfuran was formally obtained in an extremely direct manner without tedious stepwise synthesis. In addition, regio-isomeric furans were observed when substituted aryl alkynyl ketones were employed. This methodology represents a highly efficient synthetic route to electron-deficient furans for which catalytic approaches are scarce. The reaction proceeds efficiently under mild conditions with commercially available catalysts and materials.

Transition Metal-Mediated Synthesis of Monocyclic Aromatic Heterocycles

“…259 The reaction works well for either aryl-, hetaryl-, or alkyl-substituted propargylic alcohols 2-528 . Besides diethyl acetylenedicarboxylate, other alkynoates 2-528 , such as ethyl 3-phenylpropiolate and aryl alkynyl ketones, could also participate in this reaction, although they required the use of PBu 3 catalyst instead of DABCO at the first step of the sequence.…”

Tandem Reactions of Ynones: via Conjugate Addition of Nitrogen‐, Carbon‐, Oxygen‐, Boron‐, Silicon‐, Phosphorus‐, and Sulfur‐Containing Nucleophiles

“…The one‐pot procedure is an interesting strategy to prepare electron‐deficient furans through the reaction of propargyl alcohols [Eq. (78‐1)] . It involves the following reactions: (i) Michael addition 78.1 , (ii) cyclization 78.2 , (iii) rearrangement 78.3 , and (iv) 5‐ endo cyclization (Scheme ).…”

Conversion of O‐Propargyl β‐enones to 2‐Allylidene 1,3‐Diones and Furan Derivatives via [3,3]‐Sigmatropic Rearrangement

“…Ila and Junjappa et.al reported the synthesis of furan derivatives from acylketene O ‐prop‐2‐ynyl‐ S ‐methylthioketals via Claisen rearrangement . Jiang and Cao co‐workers reported silver and copper catalyszed the synthesis of furan derivatives by utilizing dimethyl but‐2‐ynedioate and propargyl alcohols in the presence of silver and copper catalytic conditions –…”