diastereoselective synthesis of perfluoroalkylated cis-spiropyrido[2,1-a]isoquinoline-1,5’-pyrimidine derivatives in good to excellent yields under mild conditions. The reaction mechanism was proposed to illustrate the formation of the diastereoisomers and proton-promoted transformation of trans-spiropyrido[2,1-a]isoquinoline-1,5’-pyrimidines to the more thermodynamically stable cis-isomers. The DFT calculation demonstrated
衍生自异喹啉和全氟烷基-2-炔酸甲酯的1,4-偶极易于与亚芳基取代的N,N-二甲基巴比妥酸反应,导致全氟烷基化的顺式-吡咯并[2,1- a ]异喹啉-1的第一个非对映选择性合成, 5'-嘧啶衍生物在温和条件下的产率高至优异。提出了反应机理以说明非对映异构体的形成和反式-吡咯并[ 2,1- a ]异喹啉-1,5'-嘧啶质子促进的转化为热力学更稳定的顺式异构体。DFT计算证明了反应的非对映选择性。
Diastereoselective Synthesis of Spirobarbiturate-Cyclopropanes through Organobase-Mediated Spirocyclopropanation of Barbiturate-Based Olefins with Benzyl Chlorides
Abstract The organobase-mediated diastereoselective spirocyclopropanation of barbiturate-based olefins with 2,4-disubstituted benzyl chlorides has been developed. The reactions were carried out efficiently to afford the desired spirobarbiturate-cyclopropanes in up to 95% yield with more than 20:1 dr in favor of anti-isomers. In order to extend synthetic utility of the spiro-products, a Lewis acid induced
Ball‐Milling‐Enabled Reactivity of Manganese Metal**
作者:William I. Nicholson、Joseph L. Howard、Giuseppina Magri、Alex C. Seastram、Adam Khan、Robert R. A. Bolt、Louis C. Morrill、Emma Richards、Duncan L. Browne
DOI:10.1002/anie.202108752
日期:2021.10.18
conditions have led to the serendipitous discovery that manganese metal can mediate the reductive dimerization of arylidene malonates. The newly uncovered process has been optimized and its mechanism explored using CV measurements, radical trapping experiments, EPR spectroscopy, and solution control reactions. This unique reactivity can also be translated to solution whereupon pre-milling of the manganese
The hypercoordinated tin reagent iPr-tricarbastannatrane is employed in B(C6F5)3-catalyzed transfer 1,4-hydrostannanylation of electron deficient olefins.
The phosphine-catalyzed [3 + 2] annulation reaction of ynones and barbiturate-derived alkenes has been developed with the assistance of a weak acid, giving functionalized spirobarbiturate-cyclopentanones in moderate to excellent yields with excellent E/Z stereoselectivity. An unprecedented [4 + 2] annulation of ynones with barbiturate-derived alkenes was also achieved in the presence of a phosphine