Synthesis of functionalized iodoalkenes using a multicomponent reaction triggered by electrophilic iodination of alkenyldiazoacetates

Ryota Kajihara, Shingo Harada, Jun Ueda, Tetsuhiro Nemoto

Index: 10.1016/j.tetlet.2018.03.063

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Abstract

Diazo compounds are frequently used as precursors of metal carbenoids and act as soft nucleophiles even without the use of metal catalysts. The resulting diazonium species may also be trapped by various nucleophiles. The introduction of an iodine functionality applicable for the coupling reaction into an alkenyl diazo compound, however, has not been reported. We developed iodoalkoxylation reactions of alkenyl diazoacetates using an electrophilic iodinating reagent and oxygen nucleophile. This catalyst-free multicomponent reaction proceeded regioselectively, furnishing trisubstituted vinyl iodides in 31% to 71% yield. The synthesized iodoalkenes were converted into the corresponding olefins with various functionalities in good yield via Suzuki-Miyaura coupling reactions with arylboronic acids under palladium catalysis to demonstrate the synthetic utility of the developed reaction sequence.