碳5-取代Adamantylidenefulvenes及碳5-取代金剛酮之面向選擇性研究

Abstract

本論文利用碳-5取代adamantylidenefulvenes (29-X) 化合物與碳-5取代金剛烷衍生物進行反應以探討取代基電子效應對面向選擇性的影響。碳-5取代adamantylidenefulvenes (29-X) 化合物與N-phenylmaleimide進行Diels-Alder環化反應，可得兩種異構物Z-31-X與E-31-X，產物比例~45:55，產率為65-76 %。此環化加成反應為熱力學控制反應，以anti-π面攻擊的產物E-31-X為主。化合物adamantylidenefulvenes (29-H) 與C60進行衍生化反應得到產率為63 % 之化合物32、33和35。此產物生成的原因是在可見光的照射下C60和分子氧所產生之singlet oxygen會與adamantylidenefulvenes (29-H) 進行 [4+2] 加成反應，再進行ene反應。 碳-5取代金剛酮 (1-X) 分別與溴丙烯 (allylbromide) 及銦 (indium) 進行反應，反應偏好從碳-5取代金剛酮 (1-X) 的syn-π面進行加成反應，當取代基拉電子能力愈強時選擇性也愈好。此結果可以Cieplak的超共軛理論解釋。 利用b-環糊精與碳-5取代金剛酮 (1-X)、溴丙烯加上銦在水中進行反應只得到唯一E型式的產物，產率為55-65 %。可能原因為銦與碳-5取代金剛酮 (1-X)、b-環糊精及溴丙烯生成錯合物，引導反應由順式面進行加成，而獲得高選擇性產物。

5-Substituted adamantylidenefulvenes and 5-substituted adamantan-2-ones were used as probes in research aimed at stereoselection in additions to trigonal carbons. The Diels-Alder reactions of 5-substituted adamantylidenefulvenes with N-phenylmaleimide gave mixtures of adducts Z-31-X and E-31-X with ratios around 45:55 and in 65-76 % yields. The cycloaddition was found to be a thermodynamic controlled reaction, and anti-attack product E-31-X was favored. The reaction of 5-substituted adamantylidenefulvenes (29-H) with C60 gave 32, 33 and 35 adducts in 63 % yield. Under irradiation with visible light in the presence of molecular oxygen and small amount of C60 the 5-substituted adamantylidenefulvenes (29-H) underwent [4+2] addition with singlet oxygen followed by ene reaction to give the isolated adducts. The reaction of 5-substituted adamantan-2-ones (1-X) with allylbromide and indium was found to be a kinetic-controlled reaction. The generation of products from the syn-face attack was discussed in terms of transition-state hyperconjugation. The allylation reaction of 5-substituted adamantan-2-ones (1-X), with allyl bromide and indium in water in the presence of b-CD, gave specifically the syn-face product. Possible reasons for this interesting result are discussed.