Addition of iodine isocyanate to olefins. Scope and synthetic utility.
Addition of iodine isocyanate to olefins. Scope and synthetic utility.
复制标题
异氰酸碘与烯烃的加成。
DOI：
10.1021/jo01278a006
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发表时间：
1967
期刊：
影响因子：
--
通讯作者：
C. Heathcock
中科院分区：
文献类型：
--
作者：
A. Hassner;M. Lorber;C. Heathcock
The stereospecific introduction of nitrogen functions via additions of iodine isocyanate to olefins is discussed with emphasis on the reagent, solvent effects, the scope of the reaction, the formation of carbamates, and syn-thetic routes to heterocyclic compounds and amino alcohols. Additions of iodine isocyanate generally proceed well with mono-, di-, and some trisubstituted olefins and can also be carried out with acetylenes. Conjugated unsaturated acids, esters, ketones, and nitriles are unreactive toward the reagent. Conjugated and noncon-jugated dienes can yield monoaddition products. The/3-iodo isocyanates can be characterized as carbamates, amine salts, or bisulfite addition compounds all of which can be transformed into aziridines. In this manner fused and spiroaziridines may be synthesized. The conversion of the isocyanate adducts to carbamates by exposure to alcohols can be sped up considerably by catalytic amounts of lithium or sodium alkoxide. The addition reaction may be employed for the stereospecific synthesis of czs-jS-amino alcohols.The modern synthetic chemist has at his disposal a variety of methods for introducing oxygen functions stereospecifically into organic molecules, notably via epoxides and ketones. For the introduction of nitro-gen functions, in particular for the stereospecific formation of bifunctional compounds, the available repertory is much more limited. Since electrophilic additions to olefins usually occur with a high degree of stereospecificity and olefins are readily available starting materials, we investigated the suitability of additions to olefins for the introduction of nitrogen functions. The method of choice became the addition of iodine isocyanate (INCO) to olefins. This reaction has been successfully utilized in recent years2-7 after it lay dormant following the initial investigation by Birckenbach and co-workers 35 years ago. 8 It has been demonstrated that the additionsgenerally occur in a stereospecific manner and that theiodine and iso-cyanate functions are introduced trans to each other and diaxially in rigid, fused cyclohexanes. 6 The iso-cyanate function can usually be converted to a carbam-ate and the resulting/3-iodo carbamates serve as con-venient precursors to aziridines. 5
