Synthetic Entry to Polyfunctionalized Molecules through the [3+2]-Cycloaddition of Thiocarbonyl Ylides

Abstract

Here we present a comprehensive study on the [3+2]-cycloaddition of thiocarbonyl ylides with a wide variety of alkenes and alkynes. The obtained dihydro- and tetrahydrothiophene products serve as exceptionally versatile intermediates providing access to thiophenes, dienes, dendralenes, and vic-quarternary carbon centers. The use of high-pressure conditions enables thermally unstable, sterically encumbered or moderately reactive substrates to undergo the cycloaddition under mild conditions, thereby increasing the yield by up to 58%. In addition, we showcase its utility by the formal syntheses of the pharmaceuticals NGB 4420 and tenilapine.

The Huisgen Reaction: Milestones of the 1,3‐Dipolar Cycloaddition

“…Besides azomethine ylides, carbonyl ylides, and thiocarbonyl ylides, mainly nitrones and nitrile oxides have been employed as 1,3‐dipoles to prepare isoxazole derivatives and to convert these into synthetically useful building blocks. G. Stork and J. E. McMurry very early used a nitrile oxide–alkyne cycloaddition to synthesize a specifically substituted isoxazole required as aldol‐equivalent building block for the synthesis of steroid derivatives .…”

Synthetic exploration of sulfinyl radicals using sulfinyl sulfones

“…They are widespread in molecules such as natural products, proteins, and pharmaceuticals, playing a central role in biology as structural elements and key mediators of biological processes 1 – 4 , and providing vital tools for organic synthesis 5 – 10 . Many methodologies and sulfur sources have been developed to install a variety of sulfur functionalities into organic molecules 11 – 14 . Among these, the use of sulfur-centered radicals to access sulfur-containing compounds has attracted considerable attention due to their ease of generation and efficiency of reaction 15 – 20 .…”

Research Progress in C—S Bond Formation Reaction of Olefins with Organic Sulfur Reagents under Photocatalyst-Free and Non-Electrochemical Conditions

“…值得一提的是, 当采用某些具有特殊结构的亚砜类化合物为原料时, 此 类转化在复杂分子合成方面表现优异 [87] . Magauer 课题 组 [88] 开发了亚砜类化合物与烯烃的[3＋2]环加成反应, 以中等至较高的产率合成了一系列四氢噻吩衍生物(Eq. 37).…”