Seven-membered rings through metal-free rearrangement mediated by hypervalent iodine.
نویسندگان
چکیده
A versatile and metal-free approach for the synthesis of carbocycles and of heterocycles bearing seven- and eight-membered rings is described. The strategy is based on ring expansion of 1-vinylcycloalkanols (or the corresponding silyl or methyl ether) mediated by the hypervalent iodine reagent HTIB (PhI(OH)OTs). Reaction conditions can be easily adjusted to give ring expansion products bearing different functional groups. A route to medium-ring lactones was also developed.
منابع مشابه
Stereoselective synthesis of 5-7 membered cyclic ethers by deiodonative ring-enlargement using hypervalent iodine reagents.
Stereoselective synthesis of 5-7 membered cyclic ethers was achieved by deiodonative ring-enlargement of cyclic ethers having an iodoalkyl substituent. The reaction took place readily under mild conditions using hypervalent iodine compounds and an acetoxy or a trifluoroacetoxy group was introduced into the rings depending on the hypervalent iodine reagent employed. The use of hexafluoroisopropa...
متن کاملHypervalent iodine mediated alkene difunctionalization of vinylphenols: diastereoselective synthesis of substituted indoles and indolizines.
A hypervalent iodine mediated alkene difunctionalization reaction of vinylphenols has been developed. The chemistry is applicable to a wide range of substitutions on both the alkene and nucleophile substrates, enabling the rapid synthesis of 3-substituted indoles and 2-substituted indolizines in good yields and high diastereoselectivities under metal-free conditions.
متن کاملFacile Oxidative Rearrangements Using Hypervalent Iodine Reagents
Aromatic substituents migrate in a novel oxidative cyclization mediated by iodine(III) reagents. 4-Arylbut-3-enoic acids are cyclized and rearranged to 4-arylfuran-2(5H)-ones by hypervalent iodine compounds in good to excellent yields under mild reaction conditions. Other ring sizes are also accessible. The mechanism of the reaction is described in detail, and calculations highlight the cationi...
متن کاملThree component one-pot synthesis of 4H-benzo-[b]-pyran derivatives using [(diacetoxyiodo)benzene] (DIB) as a hypervalent iodine catalyst
The three components one pot synthesis of 2-amino-4H-benzo-[b] -pyran derivatives were obtained in good to excellent yields within short reaction time by condensing dimedone, aldehydes and malanonitrile or ethylcyanoacetate using a catalytic amount of (diacetoxyiodo)benzene as hypervalent iodine in aqueous ethanol under reflux conditions have been discussed. This aqua mediated Knoevenagel-cyclo...
متن کاملHypervalent iodine(III)-induced oxidative [4+2] annulation of o-phenylenediamines and electron-deficient alkynes: direct synthesis of quinoxalines from alkyne substrates under metal-free conditions.
Hypervalent iodine(III)-induced oxidative [4+2] annulation of o-phenylenediamines and electron-deficient alkynes under metal-free conditions has been developed. The reaction allows for direct access to quinoxalines bearing two electron-withdrawing groups in an efficient manner.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Molecules
دوره 20 1 شماره
صفحات -
تاریخ انتشار 2015