Studies On Synthesis Of Communesin And Pd, Cu Catalyzed C-H Functionalization

This thesis mainly contains three subjects:(1) A rapid and high efficient construction of fused spiroindolenines via a tandem Mannich/intramoleculat hemiacetalization reaction has been developed and this method can be further applied into the synthesis of natural communesin and its analogues. (2) A functional-group directed Ar-Sp~2 C-H bond olefination of indoles was developed, which has also been applied in the total synthesis of Tryprostatin B. (3) Meanwhile, a novel Copper catalyzed Ar-Sp~2 C-H amination of N, N’-dimethylsbenzylamines under room temperature and air was described, which can provide o-aminal benzaldehydes in high yields. It consists of the following four chapters:Chapter 1. The progress on the synthesis of Physiological active indolines. (Review)Some general examples illustrate the power of new strategies in building skeleton of indoline alkaloids, with particular emphasis on several recent applications in natural products.Chapter 2. Stereoselective synthesis of fused spiroindolenines via tandem Mannich/Intramolecular hemiacetalization reactionThe physiological activities and progress on the synthesis of fused indolines were briefly reviewed. A novel tandem Mannich/intramolecular hemiacetalization reacton between tryptamin and salicylaldehydes was presented. This tandem reaction started from easily available materials to afford highly functionalized spiro-fused six membered indolenines in good to excellent yields with the generation of up to three new stereogenic centers (highly congested continuous spiro quaternary and two tertiary stereocenters) in excellent regio- and dia- stereoselectivities. Such access to complex polycylicindole cores may find broader applications for the diversity oriented synthesis of communeisin-like compounds for further chemical biology studies.Chapter 3. Pd catalyzed C-H olefination between indoles and allylic esterMethodologies based on Pd catalyzed C-H activation and the progress on the study of the bioactivity and previous synthetic studies of tryprostatin were reviewed in brief. A convenient and FG-directed palladium (Ⅱ)-catalyzed olefination of iodoles with allylic ester via C-H functionalization with highly regioselectivity and economics fashion was developed. In this system, the cross coupling reaction occured via β-H elimination rather than β-OAC elimination. Our research here provides a potential useful approach to construct important C-2 indole scaffolds, such as tryprostatin B and its derivatives.Chapter 4. A novel copper catalyzed C-H amination between N,N-disubstituted benzylamines and amines Under Room TemperatureMethodologies based on copper catalyzed C-H activation were briefly reviewed. The first highly selective Cu-catalyzed intermolecular C-H amination of benzylamine at room temperature under air has been developed. Herein we describes a new traceless iminium cation directing group, which lowers energy barrier of amination. And, this reaction creates an opportunity to rapid and straightforward access to the 2-amino benzaldehydes of quite importance in biological and medicinal chemistry, and sulfoximines of chiral auxiliaries as well as pivotal motifs in biologically active compounds.