Rh(I)-Catalyzed Decarbonylation of Diynones via C–C Activation: Orthogonal Synthesis of Conjugated Diynes
摘要:
Utilization of C-C bond activation as a unique mode of reactivity for constructing C-C bonds provides new strategies for preparing important organic molecules. Development of a Rh(I)-catalyzed C-C activation of diynones to synthesize symmetrical and unsymmetrical conjugated diynes through decarbonylation is reported. This C-C cleavage strategy takes advantage of the innate reactivity of conjugated ynones without relying on any ring strain or auxiliary directing group. This alkynation method also has orthogonal properties compared to typical cross-coupling reactions.
Regiodivergent Hydration–Cyclization of Diynones under Gold Catalysis
作者:Marta Solas、Miguel A. Muñoz、Samuel Suárez-Pantiga、Roberto Sanz
DOI:10.1021/acs.orglett.0c02892
日期:2020.10.2
Skipped diynones, efficiently prepared from biomass-derived ethyl lactate, undergo a tandem hydration–oxacyclization reaction under gold(I) catalysis. Reaction conditions have been developed for a switchable process that allows selective access to 4-pyrones or 3(2H)-furanonesfrom the same starting diynones. Further application of this methodology in the total synthesis of polyporapyranone B was demonstrated
An Unexpected Domino Reaction of β-Keto Sulfones with Acetylene Ketones Promoted by Base: Facile Synthesis of 3(2<i>H</i>
)-Furanones and Sulfonylbenzenes
作者:Wei Tong、Qian-Yu Li、Yan-Li Xu、Heng-Shan Wang、Yan-Yan Chen、Ying-Ming Pan
DOI:10.1002/adsc.201700830
日期:2017.11.23
An unexpected domino reaction of β‐keto sulfones with acetylene ketones has been developed. The domino reaction of β‐keto sulfones with diynones proceeded smoothly in the presence of 30 mol% K2CO3 without other additives, and afforded the novel 3(2H)‐furanone derivatives. On replacing the diynones with terminal alkyne ketones, the reaction regioselectivity was changed and sulfonylbenzenes were obtained
β-酮砜与乙炔酮发生了意想不到的多米诺反应。在没有其他添加剂的情况下,在30 mol%K 2 CO 3的存在下,β-酮砜与二炔酮的多米诺反应顺利进行,得到了新颖的3(2 H)-呋喃酮衍生物。用末端炔烃酮取代二炔酮后,反应区域选择性改变,并通过苯环化获得磺酰苯,收率很高。
Transition Metal-Free Synthesis of 3-Alkynylpyrrole-2-carboxylates<i>via</i>Michael Addition/Intramolecular Cyclodehydration
作者:Qing-hu Teng、Yan-li Xu、Ying Liang、Heng-shan Wang、Ying-chun Wang、Ying-ming Pan
DOI:10.1002/adsc.201501073
日期:2016.6.16
the synthesis of 3‐alkynylpyrrole‐2‐carboxylates from diynones and glycine esters or 2‐aminoacetophenone hydrochloride has been developed. This transformation provides a large range of substituted pyrroles in good to excellent yields with the elimination of water as the only by‐product. The detailed mechanistic studies elucidated that this transformation involves a Michaeladdition/intramolecular cyclodehydration
Phosphine-Catalyzed Synthesis of 3-Allyl-4-pyrones by the Tandem Reaction of Diynones and Allylic Alcohols
作者:Ya-Fang Ye、Wan-Wan Yang、Jing-Wen Zhang、Ji-Ya Fu、Jun-Yan Zhu、Yan-Bo Wang
DOI:10.1021/acs.joc.1c01340
日期:2021.11.5
A simple and effective tandem reaction of diynones and allylicalcohols was developed to afford functionalized 3-allyl-4-pyrones in moderate to excellent yields. This protocol underwent a Michael addition─Claisen rearrangement─O-cyclization process, which exhibited broad substrate tolerance, high regioselectivity, and atom economy under a metal-free condition. Moreover, functional transformation of
Redesign of a Pyrylium Photoredox Catalyst and Its Application to the Generation of Carbonyl Ylides
作者:Edwin Alfonzo、Felix Steven Alfonso、Aaron B. Beeler
DOI:10.1021/acs.orglett.7b01222
日期:2017.6.2
We report the exploration into photoredox generation of carbonylylides from benzylic epoxides using newly designed 4-mesityl-2,6-diphenylpyrylium tetrafluoroborate (MDPT) and 4-mesityl-2,6-di-p-tolylpyrylium tetrafluoroborate (MD(p-tolyl)PT) catalysts. These catalysts are excited at visible wavelengths, are highly robust, and exhibit some of the highest oxidation potentials reported. Their utility