Synthesis And Reaction Chemistry Of Novel Borylsilane And Aluminium Hydride

Both organohydrosilanes and organoaluminium hydrides are the hydrogenation reaction reagent compounds that are widely utilized in organic syntheses.This thesis studies on the reaction chemistry of the borylsilane with a series of allene-type unsaturated organic molecules.The aluminium hydrides with an N/Al frustrated Lewis pair(FLP)character have also been synthesized and used to study the reaction chemistry with a wide range of organic molecules and group 16 elements.The work focuses on two parts shown as follows.1.Study on reaction chemistry of a pentafluorophenylboryl group-contained aryl(silyl)aminohydrosilane with allene-type unsaturated organic moleculesPentafluorophenylboryl group-contained aryl(silyl)aminohydrosilane RSiMe(H)C(Ph)=C(C6F5)B(C6F5)2(R = N(SiMe2Ph)-2,6-iPr2C6H3,1)has been prepared with a good yield through multi-step reactions,and its reaction chemistry was studied with allene-type unsaturated organic molecules including carbodiimide,allene,ketenimine,and ketene.Compound 1 reacted with CyN=C=NCy and iPrN=C=NiPr to give seven-membered ring compounds RMeSi(CyNCH=NCy)C(Ph)=C(C6F5)B(C6F5)2(R=N(SiMe2Ph)-2,6-iPr2-C6H3)(2)and RMeSi(Me2CHNCH=NCHMe2)C(Ph)=C(C6F5)B(C6F5)2(3),respectively,in which a Si-H bond addition to the C=N bond as well as N atom coordination at the B center were found.The reaction of 1 with CH2=C=CMe2 and CH2=CH=CH(BOCMe2CMe2O)2 readily generated products RMeSi(C6F5)C(Ph)=C(C6F5)BC6F5(CH2CH=CMe2)(4)and RMeSi(C6F5)C(Ph)=C(C6F5)BC6F5(CH2CH=CH(BOCMe2CMe20)2)(5),which occurred by a B-H bond addition to the C=C double bond under a simultaneous migration of the C6F5 group from the B atom to the Si atom.The reaction of 1 with Ph2C=C=NiPr and Ph2C=C=NTMS(TMS = SiMe3)both yielded a five-membered ring compound RMeSi(N=CHCHPh2)C(Ph)=C(C6F5)B(C6F5)2(6).This product was formed via a Si-H addition to the C=N bond accompanying with an elimination of either the iPr or TMS group connected at the N atom.In addition,compound 1 reacted with Ph(Et)C=C=O to afford compounds RMeSi(OCH=CPhEt)C(Ph)=C(C6F5)B(C6F5)2(7)and RMeSi(O)C(Ph)=C(C6F5)B(C6F5)(8).The former is as a result by a Si-H addition to the C=O bond whereas the latter is formed due to a cleavage of the C-O bond followed by a migration of the C6F5 group when upon heat treatment.The compounds 2-8 have been characterized by NMR and IR spectroscopy,CHN elemental analysis,and X-ray crystallography.These studies revealed a novel reaction chemistry of compound 1.This compound might be considered as a useful hydride reagent.2.Study on synthesis and reaction chemistry of aluminium hydrides with an N/Al frustrated Lewis pair(FLP)characterA new type of aluminium dihydride[(o-TMP-C6H4)AlH(?-H)]2(10)has been prepared,which featured an N/Al frustrated Lewis pair(FLP)character.Upon heat treatment,compound 10 was transferred into a monohydride(o-TMP-C6H4)2AlH(11).Treatment of 10 with N-metyl indole at 50 0C gave(o-TMP-C6H4)Al(3-C8H5NMe)2(12)while at 80 0C another compound(o-TMP-C6H4)2Al(3-C8H5NMe)(13)was produced.Reaction of 11 with N-metyl indole at 70 ? gave 13 as well.This reaction involves a sp2-C-H bond activitation under interaction by the intramolecular N/Al frustrated Lewis pair,forming heteroaryl aluminum compound under an elimination of H2.This is a new route to the arylaluminium compound.The reaction of 10 with terminal alkyne PhCCH afforded deprotonation compound(o-TMP-C6H4)Al(C=CPh)2(15)while that with with PhC=C(Et)gave hydroalumination product(o-TMP-C6H4)AlH(CPh=CHEt)(16).The reaction of 10 was also carried out with PhC?CTMS to produce(o-TMP-C6H4)AlH(C6H5-o-CH=CSiMe3)(18)in which an initial hydroalumination happened followed by an eliminatioI of H2 through a sp2-C-H bond activitation.The reaction of 10 with ketenimine gave compounds(o-TMP-C6H4)Al(C6H4-O-CPh=CHNiPr)(21)and(o-TMP-C6H4)Al(C6H4-o-CPh=CHNDipp)(22),respectively,undergoing similiar reaction modes like that to 18?Furthermore,the reactions of 10 with organic molecules nitrile,imine,aldehyde,ketone and lactone were also investigated.Treatment of 10 with diphenylacetonitrile and DippC=NCy respectively,generated(o-TMP-C6H4)AlH(N=CHCHPh2)(19)and(o-TMP-C6H4)AlHN(Cy)-2,6-iPr2C6H3(20),both via an Al-H addition to the C?N and C=N bonds.The reactions of 10 with 2-naphthaldehyde and Ph2C=O produced[(o-TMP-C6H4)AlH(OCH2C10H7)]2(23)and[(o-TMP-C6H4)Al(OCHPh2)]2(24)respectively.When 10 was used for reacting with 2-coumaranone,compound[(o-TMP-C6H4)AlH(OC6H4-o-CH2CH2O)]2(25)was yielded as a result by an Al-H addition to the C=O bond followed by a cleavage of C-O bond.Finally,we have finished the reactions of 10 with aniline,indole,phenol and group 16 elements of S and Se.In these reactions the deprotonation products as[(o-TMP-C6H4)AlHNH-2,6-iPr2C6H3]2(28),[(o-TMP-C6H4)Al(NC8H6)(?-H)]2(29),[(o-TMP-C6H4)Al(NC8H6)2](30),(o-TMP-C6H4)AlHOC6F5(31),and(o-TMP-C6H4)Al(OC6F5)2(32)were formed.Another type of compounds as[(o-TMP-C6H4)Al]4S4(26)and[(o-TMP-C6H4)Al]4Se4(27)was obtained under reduction.All of the new products were characterized by NMR and IR spectroscopy and CHN elemental analysis,of which compounds 10-13,18-24,24-26 and 28-29 were further characterized by X-ray crystallography.All of these results manifest a rich reaction chemistry of the aluminium hydrides with the FLP character.