One‐Step Addition of Sulfonic Acids to Acetylene Derivatives: An Alternative and Stereoselective Approach to Vinyl Triflates and Fluorosulfonates

Abstract

Acetylenic acids and esters as well as acetylenic ketones were efficiently and stereoselectively converted in one step to the corresponding vinyl triflates or fluorosulfonates in triflic or fluorosulfonic acids. Depending on the reaction conditions the E or the Z isomer can be obtained very conveniently in high isolated yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Vinyl and Aryl Sulfonates: Preparations and Applications in Total Synthesis

“…Based on these pioneering works and capitalizing on their expertise in alkyne [30] and superacid [31] chemistries, Sommer and Pale recently reported an efficient and highly stereoselective onestep method for the synthesis of carbonylated vinyl triflates (Scheme 24) [32]. Treatment of acetylenic carbonyl derivatives by an excess of fluorosulfonic acid or triflic acid leads to the direct regio-and stereoselective addition of the sulfonic acid to the alkyne moiety.…”

Transition Metal-Free-Catalyzed Regioselective Reversal in the Cyclization of 2-Diazo-3,5-dioxo-6-ynoates/ynones/ynamide: Synthesis of Diazo γ-Pyrones and Diazo 3(2H)-Furanones

“…在 HSbF 6 作为催化剂的情况下, 2-重氮-3,5-二氧代-6-炔酮(炔酯、炔酰胺)1 首先质子化形 成双正离子活性中间体 5. 随后, 羰基氧原子进攻双正 离子活性中间体中带正电荷的烯基碳 [11] , 经 6-exo-dig 环化提供重氮-吡喃酮 2 (Method A, Scheme 2). 在 HOAc/DCE 的弱酸反应体系中, 2-重氮-3,5-二氧代-6-炔 酮(炔酯、炔酰胺)1 首先质子化形成 盐 5A [12] .…”

Triflic Acid

“…4 The stereoselectivity could be controlled by adjusting the reaction conditions. Moreover, the generated vinyl triflates are very reactive intermediates towards metal cross-coupling reactions.…”