Copper/Cobalt Catalyzed Divergent Transformations Of Conjugated Enynes

In this dissertation,we discussed a controllable divergent transformations of conjugated enynes.A serials of synthetic useful and medicinal valuable organosilanes,organoboranes and fluoro-containing compounds were prepared by this strategy.Major work could be divided into two parts:Part one:divergent transformations based on conjugate addition to polar enynes:In this part,a serials of compounds with vinylsilane,allylsiane or vinylborane moieties under the copper-catalyzed conjugate addition of silyborane and bis(pinacolato)diboron to polar enynes were prepared.1.Under the catalysis of CuCl,a serials of multi-functional Z-specific 1,3-bis(silyl)propene were prepared by the conjugate addtion of silylborane to conjugated enyoate analogues.By using chiral pyridine-oxaline based compounds as ligands,chiral 1,3-disilylpropenes could be obtained in excellent yields with high ee's.Techniques such as 1H NMR and GC-MS were used to study the reaction mechanism.The 1,3-bis(silyl)propene could be transformed into 1,6-or 1,7-diester via desilylation/nucleophilic addition process.2.Under the catalysis of CuBr/K2CO3,conjugate addition of silylborane to poloar enynes could be retained at the 1,4-addition stage,therefore furnished the ?-silyldienoates.The products could also be conveniently transformed to analogues of a biologically active molecule.3.Under the CuCl/1,10-phenathroline system,high stereoselective tri-substituted vinylborane could be obtained via cascade double proto-borylations/proto-deborylation reaction of polar enynes.A plausible mechanism was proposed according to control experiments and deuterated experiments.The vinylborane could be converted to corresponding methyl alkene with configuration retained via palladium-catalyzed Suzuki-type coupling with methyl iodide,or with configuration inversed in MeLi/I2/base system.These stereo-defined methyl alkenes are widely existed in natural product.Part two:divergent transformations based on radical difunctionalization of nonpolar conjugated enynesTraditional radical difunctionalization of alkenes were employed to nonpolar conjugated enynes to achieve selective cobalt-catalyzed peroxytrifluoromethylation of alkene site by using Langlois reagent as trifluomethylation reagent and tert-butyl peroxide as oxidant and coupling partner.The produced peroxide could be easily converted to trifluoromethyl-substituted 3°-alcohols.