Ring-Opening of Vinylcyclopropane-1,1-dicarboxylates by Boronic Acids under Ligandless Palladium Catalysis in Neat Water

Fe-Catalyzed Hydroallylation of Unactivated Alkenes with Vinyl Cyclopropanes

Catalytic, reductive C-C bond formation between alkenes and vinyl cyclopropane (VCP) through hydrogen atom transfer (MHAT) is developed. Despite VCP's use as probes in radical-clock experiments, translation of this manifold into synthetic methods for accessing elusive C-C bonds remains largely unexplored. This work represents the first foray into this front where the high chemoselectivity of MHAT for alkene over VCP was pivotal for realizing the strategy. This method exhibits a broad scope, high functional group tolerance, and useful applications.

Ligand-free nickel catalyzed perfluoroalkylation of arenes and heteroarenes

We describe a "ligand-free" Ni-catalyzed perfluoroalkylation of heteroarenes to produce a diverse array of trfiluoromethyl, pentafluoroethyl and heptafluoropropyl adducts. Catalysis proceeds at room temperature via a radical pathway. The catalytic protocol is distinguished by its simplicity, and its wide scope demonstrates the potential in the late-stage functionalization of drug analogues and peptides.

Generation and Reactions of ε-Carbonyl Cations via Group 13 Catalysis

The generation of ε-carbonyl cations and their reactions with nucleophiles is accomplished readily without transition metal cation stabilization, using the ε-bromide dienoate or dienone starting materials and GaCl3 or InCl3 catalysis. Arene nucleophiles are somewhat more straightforward than allyltrimethylsilane, but allyltrimethylsilane and propiophenone trimethysilyl enol ether each react successfully with InCl3 catalysis. The viability of these cations is supported by DFT calculations.

Solvated Nickel Complexes as Stoichiometric and Catalytic Perfluoroalkylation Agents*

The acetonitrile-solvated [(MeCN)Ni(C₂ F₅ )₃ ]^- was prepared in order to compare and contrast its reactivity with the known [(MeCN)Ni(CF₃ )₃ ]^- towards organic electrophiles. Both [(MeCN)Ni(CF₃ )₃ ]^- and [(MeCN)Ni(C₂ F₅ )₃ ]^- successfully react with aryl iodonium and diazonium salts as well as alkynyl iodonium salts to give fluoroalkylated organic products. Electrochemical analysis of [(MeCN)Ni^II (C₂ F₅ )₃ ]^- suggests that, upon electro-oxidation to [(MeCN)_n Ni^III (C₂ F₅ )₃ ], reductive homolysis of a perfluoroethyl radical occurs, with the concomitant formation of [(MeCN)₂ Ni^II (C₂ F₅ )₂ ]. Catalytic C-H trifluoromethylations of electron-rich arenes were successfully achieved using either [(MeCN)Ni(CF₃ )₃ ]^- or the related [Ni(CF₃ )₄ ]^2- . Stoichiometric reactions of the solvated nickel complexes reveal that "ligandless" nickel is exceptionally capable of serving as reservoir of CF₃ groups under catalytically relevant conditions.

Catalytic allylic functionalization via π-allyl palladium chemistry

This review highlights the palladium-catalyzed allylic C–H functionalizations via π-allyl palladium reported from early 2014 to present date.

Synthetic applications of vinyl cyclopropane opening

Vinyl cyclopropanes are amongst the most useful building blocks in organic synthesis. Their easy opening and capacity to generate dipoles have been exploited for the synthesis of cyclopentanes with good yields and sometimes excellent stereoselectivities. In this review we give an overview of their applications, focusing on the present century.

Pd-Catalyzed diastereoselective [3 + 2] cycloaddition of vinylcyclopropanes with sulfamate-derived cyclic imines

The palladium-catalyzed diastereoselective [3 + 2] cycloaddition reaction of vinylcyclopropanes with sulfamate-derived cyclic imines worked efficiently under mild conditions, providing sulfamate-fused pyrrolidines in good to excellent yields.

Ring-opening polymerization of donor–acceptor cyclopropanes catalyzed by Lewis acids

Ring-opening polymerization of a variety of cyclopropane derivatives catalyzed by Lewis acids has been investigated.

Palladium-catalyzed highly atom-economical allylation of oxindoles with vinyl cyclopropanes

A highly atom-economical allylation of oxindoles with vinyl cyclopropanes catalyzed by Pd(PPh3)4 has been developed, setting up a practical venue for the installation of an all-carbon quaternary center at the 3-position in oxindoles under mild reaction conditions. Importantly, the reaction proceeded well without any additives and no waste was produced, affording linear products with high regioselectivities (>20 : 1). Enantioselective allylic alkylation has also been realized to provide the desired products in good yields and 35% ee.