Versatile and Iodine Atom-Economic Co-Iodination of Alkenes

Abstract

Molecular iodine, I(2), is readily converted into 2 equiv of acetyl hypoiodite (CH(3)CO(2)I) via oxidation by (diacetoxyiodo)benzene (DAIB) followed by trapping of the iodide ion by acetoxyphenyl iodonium ion formed. The in situ generated CH(3)CO(2)I is utilized for the synthesis of 1,2-iodo-cofunctionalized derivatives of a variety of alkenes. Conversion of both iodine atoms of I(2) to I(+) sources results in 100% iodine atom economy for the reported iodo-cofunctionalization of alkenes.

Iodine‐ and PhI(OAc)2‐Mediated Multicomponent Synthesis of (E)‐1,3‐Diphenyl‐1‐butene Derivatives

“…[37,38] To the best of our knowledge, this is the first report on the opening of the thiiranium ring with an alkene. As in the case of the first route, the carbocation intermediate then reacts with another molecule of the styrene component to give benzylic carbocation III.…”

“…[37,38] This intermediate then reacts with the styrene to Scheme 3. The reaction commences with the formation of the hypervalent intermediate II.…”

“…Parallel to this route, disulfide VIII could also be formed and decomposed into the electrophilic intermediate IX upon reaction with AcOI, which is generated in situ from the reaction of DIB and iodine. [37,38] This intermediate then reacts with the styrene to Scheme 3. Proposed mechanism of the dimerization styrene to provide dimer 7.…”

Alternative synthesis of 3-acetyl, 3-epoxy, and 3-formyl chlorins from a 3-vinyl chlorin, methyl pyropheophorbide-a, via iodination

“…36 Similarly, the vinyl group at the C3-position of 1 can also be converted into the C3-[(1-hydroxy-2-iodo)ethyl], C3-[(1-methoxy-2-iodo)ethyl] and C3-[(1-ethoxy-2-iodo)ethyl] groups by the I 2 -PIFA system (Scheme 1). 35 Compound 1 was mixed with I 2 (1.2 equiv) and PIFA (0.52 equiv) in 1,2-dichloroethane, followed by stirring at room temperature for 1 h. Then ethylene glycol was added to this solution, and an additional stirring afforded an ethylene glycol adduct 2, possessing a [1-(2-hydroxyethyloxy)-2-iodo]ethyl moiety at the C3-position, in 50% isolated yield.…”

Total Syntheses of Heimiol A, Hopeahainol D, and Constrained Analogues

“…Unfortunately, none afforded any evidence of cyclized material irrespective of the rate and/or order of addition. However, we found that if electrophilic iodine in the form of iodine/hypoiodide was generated in situ either by reacting PhI(OAc) 2 with I 2 or under heterogeneous conditions with Oxone® and KI, [12] the desired [3.2.2]-bicyclic system of 16 could be formed in modest amounts (~20% in the latter case) alongside several uncharacterized side-products suggestive of over- and/or non-selective halogenation. While this finding was encouraging, a superior material throughput was needed for effective prosecution of the sequence.…”