Study On Addition Reaction Of Carbon-carbon Unsaturated Bonds Based On Organoboron Reagents

As we all know,organic boric acid is widely used as a special organic-metal reagent in modern organic synthesis.The coupling reaction is dominant involving organic boronic acid,alkenyl boron of sp2 hybridized is dominant in organic boron reagent,therefore,the development of new alkenyl boron reagents has become a central issue.We have developed a new Cu(I)catalyst which can catalyst hydroboration of some terminal alkynes with HB(pin)by highly efficiency,alkenyl boron compounds are obtained under mild conditions with high ?-region and trans-stereoselectivity.The catalyst we developed is a bidentate copper catalyst containing nitrogen heterocyclic carbene and phosphinimine,the effect of IPr-Cu-NPtBu3 and SIPr-Cu-NPtBu3 is the best among many ligand combinations,we have characterized its structure by NMR and X-ray diffraction and studied its catalytic mechanism.The results showed that copper-hydrogen intermediate IPr-Cu-H or SIPr-Cu-H directly interacting with C?C,whereas IPr-Cu-H or SIPr-Cu-H is generated by the interact IPr-Cu-NPtBu3 or SIPr-Cu-NPtBu3 with HB(pin).As a coupling reagent,the core is that the organic residue of organoboron reagent is transferred to the transition metal by transmetallation for the construction of a new chemical bond.We have designed a method for the preparation of poly-substituted allyl alcohol compounds by coupling ?-allyl palladium,which is an intermediate in the bifunctionalization of alkenes,with OH as a nucleophile in organoboronic acid based on the understanding of palladium-catalyzed alkene bifunctional reaction.Due to the unique structural characteristics of the alkene compounds,there are chemical,regional and stereo-selectivity problems in this reaction.In order to achieve high selectivity,we introduced the special substituent(Ph SO2)into the simple alkene to regulation the react sites.We have developed the bifunctional reaction of phenyl sulfone based alkenes with phenyl boronic acid and aryl iodides under palladium catalysis and prepared a series of poly-substituted allylic alcohols with high regional and stereoselectivity.In order to confirm the existence of ?-allyl palladium intermediate,we have isolated the ?-allyl palladium intermediate and characterized its structure by NMR and X-ray single crystal diffraction.The results show that the control group FG and aryl group are at trans-configuration.In order to further confirm the reaction through the ?-allyl palladium,we also use the isolated ?-allyl palladium intermediate as a catalyst to catalyze the bifunctionalization of alkene and obtain a better catalytic effect than the precursor catalyst.We have also tried the alkene bifunctional reaction of carboxylic acids and amine as nucleophiles and obtain the corresponding allyl ester and allyl amine compounds after successfully preparing a series of poly-substituted allyl alcohol compounds using OH as the nucleophile in phenylboronic acid.In order to further confirm the application value of poly-substituted allylic alcohol compounds,we also made its derivation research.Starting from allyl alcohol,the corresponding chemical bond conversion can be achieved by simple treatment,and new C-C,C-Br and C-N bonds are constructed to obtain allyl alcohol esters,allyl bromide and allyl amine respectively,and these allyl compounds are also useful building blocks for organic synthesis.