β-硝基苯乙烯系列物之1,3-雙偶極合環反應與三乙基鋁或三乙基硼誘發烷基碘化物和α,β-不飽和烯類之自由基反應

劉景原(Jing-Yuan Liu)

指導教授 ： 姚清發

國立臺灣師範大學/理學院/化學系/博士(2002年)

摘要

無資料

關鍵字

三乙基鋁 ； 三乙基硼 ； 1,3-雙偶極合環反應 ； β-硝基苯乙烯

並列摘要

Part 1
An Improved, Easy and Efficient Method for the Generation of Nitrile Oxides From Nitronates for in situ 1,3-Dipolar Cycloaddition
The Michael addition of the diethyl allyl malonate anion to β-nitrostyrenes 1 generated nitronates 5. Nitronates 5 could be converted into nitrile oxides 7 to undergo intramolecular nitrile oxide–olefin cycloaddition (INOC) to form medium to high yields (51–95%) of five-membered carbocycles 8 and 9 by using ethyl chloroformate in the presence of a catalytic amount of 4-dimethylaminopyridine (DMAP). High yields (91%) of tricyclic compounds 11 and 12 were obtained when 1a reacted with the anion of 10 under similar experimental conditions and procedures.
Part 2
One-Pot Synthesis of Five-membered Cyclic Ethers via intramolecular Nitrile Oxide-Olefin Cycloaddition (INOC) or Intramolecular Alkoxycarbonyl Nitronate-Olefin Cycloaddition (IAOC) by the Use of Methyl Chloroformate
Reaction of β-nitrostyrenes 6 with allyl alcohol and base generated nitronate 7, which can be converted into methoxycarbonyl nitronates 12 by treating the solution with methyl chloroformate and catalytic amount of 4-dimethylaminopyridine (DMAP) in the presence of different amounts of triethylamine. Intermediates 12 can ethier undergo intramolecular alkoxycarbonyl nitronate-olefin cycloaddition (IAOC) to generate highly stereoselective product trans-4 or undergo INOC to yield trans-4 and cis-4. The application of this improved methodology to synthesize different heterocyclic products 16 and 17 is reported.
Part 3
Triethylaluminum–Induced Free-Radical Reactions of Alkyl Iodides and β-Nitrostyrenes
Reactions of (E)-β-nitrostyrenes 1 with triethylaluminum Et3Al 2 and alkyl iodide RI 3, 4, or 5 in the presence of benzoyl peroxide in diethyl ether solution at room temperature give 60-100% of the different (E)- alkene 6, 7, or 8. Under similar conditions, 95% of 1-adamantyl-2-(4-methoxyphenyl)ethene 10 or 80% 1-(4-oxoadamantyl)-2-(4-methoxyphenyl)ethene 12 also can be easily prepared by using 1-iodoadamantane 9 or 5-iodo-2-adamantanone 11 and 2.
Part 4
Triethylaluminum- or Triethylborane– Induced Free Radical Reaction of Alkyl Iodides and α,β-Unsaturated Compounds
A series of α,β-unsaturated compounds 1a-c, 9, 13, and 17 were used as reactants in free radical conjugate addition reactions with different radicals generated from alkyl iodides such as 3, 4, or 5 in the presence of triethylborane–oxygen in air or via the use of triethylaluminum–benzoyl peroxide as a free radical initiator. When the reactions were carried out using triethylborane–air, the products, in most cases, were clean and were easily purified. However, higher yields of the 1,4-adducts and less side reactions occurred when less reactive substrates were used as a Michael acceptor in reactions with triethylaluminum-benzoyl peroxide and alkyl iodide under similar conditions. A mechanism for this type reaction is proposed in Scheme 1.

並列關鍵字

triethylaluminum ； triethylborane ； 1,3-dipolar cycloaddition ； β-nitrostyrene

參考文獻

(1) (a) Corey, E. J.; Esteicher, H. J. Am. Chem. Soc. 1978, 100, 6294. (b) Seebach, D.; Colvin, E. W.; Well, T. Chimia 1979, 33, 1. (c) Barrett, A. G. M.; Graboski, G. G. Chem. Rev. 1986, 86, 751. (d) Rosini, G.; Ballini, R. Synthesis 1988, 833. (e) Several articals in tetrahedron Symposia-in Print 41, “Nitroalkanes and Nitroalkenes in Synthesis”, Tetrahedron 1990, 46 (21), Barrett, A. G. M. Ed. (f) Barrett, A. G. M. Chem. Soc. Rev. 1991, 20, 95.

(1) (a) Corey, E. J.; Estreicher, H. J. Am. Chem. Soc. 1978, 100, 6294. (b) Seebach, D.; Colvin, E. W.; Weller, T. Chimia 1979, 33, 1. (c) Barrett, A. G. M.; Graboski, G. G. Chem. Rev. 1986, 86, 751. (d) Rosini, G.; Ballini, R. Synthesis 1988, 833. (e) Several articles in Tetrahedron Symposia-in-Print 41, “Nitroalkanes and Nitroalkenes in Synthesis”, Tetrahedron 1990, 46 (21), Barrett, A. G. M. Ed. (f) Barrett, A. G. M. Chem. Soc. Rev. 1991, 20, 95.

(3) Mukaiyama, T.; Hoshino, T. J. Am. Chem. Soc. 1960, 82, 5339.

(14) Hassner, A.; Friedman, O.; Dehaen, W. Liebigs Ann. 1997, 587.

(16) Hofle, G.; Steglich, w.; Vorbruggen, H. Angew. Chem. Int. Ed. Engl. 1978, 17, 569.