Scope and Mechanism for Lewis Acid-Catalyzed Cycloadditions of Aldehydes and Donor−Acceptor Cyclopropanes: Evidence for a Stereospecific Intimate Ion Pair Pathway
作者:Patrick D. Pohlhaus、Shanina D. Sanders、Andrew T. Parsons、Wei Li、Jeffrey S. Johnson
DOI:10.1021/ja8015928
日期:2008.7.1
In this work, the one-step diastereoselective synthesis of cis-2,5-disubstituted tetrahydrofuransviaLewis acid catalyzed [3 + 2] cycloadditions of donor-acceptor (D-A) cyclopropanes and aldehydes is described. The scope and limitations with respect to both reaction partners are provided. A detailed examination of the mechanism has been performed, including stereochemical analysis and electronic profiling
Design, Preparation, X-ray Crystal Structure, and Reactivity of <i>o</i>-Alkoxyphenyliodonium Bis(methoxycarbonyl)methanide, a Highly Soluble Carbene Precursor
作者:Chenjie Zhu、Akira Yoshimura、Lei Ji、Yunyang Wei、Victor N. Nemykin、Viktor V. Zhdankin
DOI:10.1021/ol301268j
日期:2012.6.15
The preparation, X-ray structure, and reactivity of new, highly soluble, and reactive iodonium ylides derived from malonate methyl ester and bearing an ortho substituent on the phenyl ring are reported. These new reagents show higher reactivity than common phenyliodonium ylides in the Rh-catalyzed cyclopropanation, C–H insertion, and transylidation reactions under homogeneous conditions.
Trifluoromethylation of vinylcyclopropanes (VCPs) has been developed under mild reaction conditions to synthesize allylic trifluoromethylated derivatives with high yield and E/Z selectivity using visible light photo-redox catalysis and Langlois reagent (CF3SO2Na) as a trifluoromethylation source. Further, we demonstrate a gram scale synthesis procedure for a trifluoromethylation of vinylcyclopropane
乙烯基环丙烷(VCP)的三氟甲基化已开发出来,可以在温和的反应条件下,使用可见光氧化还原催化和朗格洛斯试剂(CF 3 SO 2 Na)作为三氟甲基化源,以高收率和E / Z选择性合成烯丙基三氟甲基化衍生物。此外,我们证明了乙烯基环丙烷的三氟甲基化的克级合成程序。
Organophotocatalyzed Alkyl/Arylsulfonylation of Vinylcyclopropanes
A direct allylic sulfonylation reaction: Allyl sulfones are an essential pharmacophore in many bioactive compounds. We report a practical, straightforward organophotocatalyzed methodology for accessing miscellaneously functionalized allyl sulfone derivatives using inexpensive and bench-stable sodium sulfinate salts under mild conditions to combat their synthetic barrier.