42311-14-8Relevant academic research and scientific papers
A new protocol for nickel-catalysed regio- and stereoselective hydrocyanation of allenes
Arai, Shigeru,Hori, Hiroto,Amako, Yuka,Nishida, Atsushi
, p. 7493 - 7496 (2015/05/04)
Regio- and stereoselective hydrocyanation under nickel catalysis is described. This report shows that allenyl C-C double bonds are discriminated and converted to the corresponding carbonitriles as a single product. The key functionalities for achieving high regio- and stereocontrol are aryl and cyclopropyl groups in the substrates. This journal is
Cationic carbenoid rearrangement of 2-phenyl substituted gem-dihalogenospiropentanes
Sedenkova, Kseniya N.,Averina, Elena B.,Grishin, Yuri K.,Rybakov, Victor B.,Kuznetzova, Tamara S.,Zefirov, Nikolay S.
experimental part, p. 4145 - 4150 (2010/09/10)
The series of 2-phenyl- and 2,2-diphenyl gem-dihalogenospiropentanes were employed as model compounds to study the carbenoid rearrangement with the use of methyllithium. The scope and limitations of this skeletal rearrangement are outlined and its mechani
Nucleophilic substitutions of 1-alkenylcyclopropyl esters and 1-alkynylcyclopropyl chlorides catalyzed by palladium(0)
Stolle, Andreas,Ollivier, Jean,Piras, Pier Paolo,Salaün, Jacques,De Meijere, Armin
, p. 4051 - 4067 (2007/10/02)
The 1-ethenylcyclopropylsulfonates 2e,f and 2-cyclopropylideneethyl esters 10b,c, readily available from cyclopropanone hemiacetal 1, undergo regioselective Pd(0) catalyzed nucleophilic substitution via the unsymmetric 1,1-dimethylene-π-allyl complex 23. With stabilized anions (enolates of malonic ester, β-dicarbonyl compounds, β-sulfonyl ester, and Schiff bases as well as acetate anion, sulfonamide anion, etc.) the nucleophilic substitution occurs at the terminal vinylic position exclusively, providing cyclopropylideneethyl derivatives as building blocks of high synthetic potential. Competition experiments have disclosed that 1-ethenylcyclopropyl tosylate (2e) and cyclopropylideneethyl acetate (10b) are more reactive than dimethylallyl acetates 19 and 22, respectively. Use of chiral phosphines as ligands in the palladium catalyst can provide optically active methylenecyclopropane derivatives. With phenyl-, methyl-, and even n-butylzinc chloride as nucleophiles, the reaction apparently proceeds with initial transfer of the organic residue to palladium, followed by reductive elimination entailing tertiary substitution on the cyclopropane ring exclusively; the same type of product is obtained with azide and bis(trimethylsilyl)amide. But the site of hydride attack to yield reduction products depends on the hydride source. 1-Alkynylcyclopropyl chlorides 12, 13, and 14 react only with organozinc chlorides (nonstabilized nucleophiles) to provide mixtures of ethenylidenecyclopropanes 65 and alkynylcyclopropanes 66, via the σ-palladium complexes 69 and 70, while chloride 15 undergoes mainly reduction. Other transition metal catalysts (Ni, Mo) also induce substitutions, but with poorer regioselectivity.
