Visible-Light-Induced Sulfur-Alkenylation of Alkenes
作者:Qi Xu、Xiaoxuan Zhou、Si Zhang、Ling Pan、Qun Liu、Yifei Li
DOI:10.1021/acs.orglett.1c01596
日期:2021.6.18
proceed in a highly regio- and stereospecific manner involving the visible-light-induced conversion of a ketene dithioacetal to the thiavinyl 1,3-dipole intermediate, followed by a formal [3 + 2] cycloaddition and C–S bond cleavage. Furthermore, it is also an efficient approach for the late-stage functionalization of natural products and complex molecules, even being induced by sunlight under ambient
BF3·OEt2-mediated alkenylation of pyrroles with α-oxo ketene dithioacetals
作者:Xiaoge Yang、Kaikai Wu、Zhengkun Yu
DOI:10.1016/j.tetlet.2015.05.102
日期:2015.7
BF3·OEt2-mediated alkenylation of pyrroles with α-oxo ketene dithioacetals was efficiently realized, affording mono- and disubstituted ketene pyrrolyl acetals. In the cases of using N-unprotected pyrrole, the reactions gave ketene bipyrrolyl acetals as well as N,O-chelated BF2 complexes. Diverse C–S transformations were achieved for the monosubstituted products, yielding N-heterocycles or multisubstituted
Brønsted Acid-Mediated Annulation of α-Oxo Ketene Dithioacetals with Pyrroles: Efficient Synthesis of Structurally Diverse Cyclopenta[<i>b</i>]pyrroles
Brønstedacid‐mediated annulation of internal olefins α‐oxo ketene dithioacetals to pyrroles was efficiently achieved to afford cyclopenta[b]pyrroles. A pair of Brønstedacids with acid strengths, that is, trifluoroacetic acid, and para‐toluenesulfonic acid hydrate, were applied to promote the annulation reactions. The resultant products were readily oxidized to sulfones by meta‐chloroperoxybenzoic
有效地实现了布朗斯台德酸介导的内烯烃α-氧代乙烯酮二硫缩醛与吡咯的环化反应,得到环戊[ b ]吡咯。一对具有酸强度的布朗斯台德酸,即三氟乙酸和对甲苯磺酸水合物,被用于促进环化反应。生成的产物很容易被间氯过氧苯甲酸氧化成砜。随后用1,8-二氮杂双环[5.4.0]十一碳-7-烯处理得到脱硫的烯烃中间体脱硫的末端烯烃或[2 + 2]环加成产物。本协议提供了在温和条件下易于访问结构多样的环戊[ b ]吡咯衍生物的方法。
One-Pot Synthesis of 2,4-Diacyl Thiophenes from α-Oxo Ketene Dithioacetals and Propargylic Alcohols
作者:Jian Xue、Li-Gang Bai、Liang Zhang、Yue Zhou、Xiao-Long Lin、Neng-Jie Mou、Dong-Rong Xiao、Qun-Li Luo
DOI:10.1021/acs.joc.0c01093
日期:2020.8.7
Although thiophenes having various functionalities are the basic structural units in numerous bioactive compounds and optoelectronic materials, synthetic routes to acylated thiophenes from aliphatic sulfur-containing starting materials are still rare. In particular, there have been no reports concerning the straightforward synthesis of 2,4-diacylthiophenes from alkynes. Herein, we describe a highly
palladium(0)-catalyzed, Cu(I)-mediated synthetic route to trisubstituted olefins and conjugate dienes has been developed via oxo directing Liebeskind–Srogl cross-coupling reactions of gem-dihaloolefin-type α-oxo ketene dithioacetals with aryl and alkenylboronic acids. The synthetic protocol has demonstrated rare examples of transition-metal-promoted transformations of ketene dithioacetals, providing a novel route to