作者:Akira Yoshimura、Steven R. Koski、Brent J. Kastern、Jonathan M. Fuchs、T. Nicholas Jones、Roza Y. Yusubova、Victor N. Nemykin、Viktor V. Zhdankin
DOI:10.1002/chem.201402372
日期:2014.5.12
An efficient, transition metal‐free procedure for the cyclopropanation of alkenes using malononitrile and the LiI‐tBuOCl combination under mild reaction conditions is described. The reaction mechanism most likely involves tBuOI generated in situ from LiI and tBuOCl. The utility of this new methodology has been demonstrated by the synthesis of a potential HIV‐1 RT inhibitor.
Sequential ATRA/Reductive Cyclopropanation Reactions with a Ruthenium Catalyst in the Presence of Manganese
作者:Mariano A. Fernández-Zúmel、Charlotte Buron、Kay Severin
DOI:10.1002/ejoc.201100175
日期:2011.4
addition (ATRA) reactions of ethyl trichloroacetate, dichloromalononitrile, or diethyl 2,2-dichloromalonate with olefins followed by dechlorination have provided functionalized cyclopropanes in one step. The RuIII complex [Cp*RuCl2(PPh3)] was used as a catalyst precursor and commercial Mn powder as reducing agent. Reactions with the less activated substrate ethyl dichloroacetate gave ATRA products with
The intermolecular cyclopropanation of 2‐aryl and 2‐styryl substituted ethenesulfonyl fluorides with active cyano‐containing methylenecompounds was described. This reaction proceeds via carbon‐sulfur bond cleavage under metal‐free conditions in up to 99% yield, affording a variety of nitrile‐substituted cyclopropanes with high diastereoselectivity.
Hypoiodite-Mediated Catalytic Cyclopropanation of Alkenes with Malononitrile
作者:Akira Yoshimura、T. Nicholas Jones、Mekhman S. Yusubov、Viktor V. Zhdankin
DOI:10.1002/adsc.201400627
日期:2014.11.3
AbstractAn efficient synthetic procedure for dicyano‐cyclopropanation of alkenes using catalytic amounts of molecular iodine as a precatalyst and tert‐butyl hydroperoxide (TBHP) as a terminal oxidant under mild conditions has been developed. This catalytic reaction works especially well for the aryl‐substituted double bond affording products of cyclopropanation in high yields. A catalytic cycle based on the generated in situ hypoiodite species has been proposed.magnified image