| Summary: | 博士 === 輔仁大學 === 化學系 === 103 === This thesis is divided into three topics.
Topic I：
1-Phenyl camphor-based chiral cyclopropene 49 was synthesized by reacting 1,1,2-tribromo-2-phenylcyclopropane with methyllithium followed by adding (R)-(+)-camphor. Compound 49 was trapped with thiophenol to form three stereoisomers 52, 53 and 54. The thiolated cyclopropane derivatives were converted to cyclopropyl sulfones by treatment with m-chloroperbenzoic acid and the resulting cyclopropyl sulfones were then reacted with NaH to remove the camphor auxiliary to give the optically pure cyclopropanes 56, ent-56, 58 and ent-58. Photooxidation of cyclopropene 49 resulted in the formation of the enone 60a and the α,β-unsaturated spiro ether enone 61. In the presence of AlCl3, the enone 60a underwent ring expansion to give the [3.2.1]bicyclic hydroxyl ketone 64. On the other hand, compound 60a underwent Michael addition with PhSNa to give 65 and 66 with a ratio of 1:1. Compound 65 and 66 treated with m-chloroperbenzoic acid to give sufoxides and sulfones. In the presence of AlCl3, compound 65 and 66 underwent ring expansion to obtain [3.2.1]bicyclic sulfoxides and [3.2.1]bicyclic sulfones.
The mixture of 1,3-fused bicyclic camphor-based chiral cyclopropenes (7R)-78a and (7S)-78b treated with PhSH for 1 h to give compounds 79 and 80 with a ratio of 1:1. When the mixture (7R)-78a and (7S)-78b reacted with PhSH for 12 h, a conjugated diene adduct 81 was formed. Oxidation of the mixture (7R)-78a and (7S)-78b resulted an enone adduct 82.
Topic II：
1-Thienylcyclopropene (31) was synthesized by treatment of 1,1,2-tribromo-2-thienylcyclopropane (27) with methyllithium followed by protonation. Compound 31 was trapped with Cp to form compound 32. In the meantime, a head-to-head [2+2] adduct 33 was also afforded. Compound 33 underwent ring opening reaction to give 1,2-dithienylcyclohexa-1,4-diene (34) at room temperature. When compound 31 reacted in the absence of Cp, compounds 33 and 34 were yielded.
1-Thienyl-2-trimethylsilylcyclopropene (36) was trapped with Cp to give [4+2] cycloaddition adduct 37. The structure was confirmed by X-ray analysis as an endo-adduct.
Topic III：
In this topic, we provide an efficient method to synthesize 2-nitrothiophene derivatives. 2-Styrylthiophene (32) reacted with NIS to give iodo adduct 33, which was treated with AgNO3 to yield a 2-nitrothiophene derivative 34. An electron donating group (OMe) at the para-position of the phenyl was amenable to this transformation. The reaction of bis thiophene 38 with NBS afforded dibromo adduct 40. Treatment of compound 40 with 2eq AgNO3 afforded mono nitration adduct 41.
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