新型取代基炔类分子的合成及其与B(C6F5)3的反应

合成了5种不同取代基的炔类化合物Mes2HSiC≡CPh(1,Mes=2,4,6-Me3C6H2)、[tBuC(NAr)2]GeC≡CPh(2,Ar=2,6-iPr2C6H3)、[PhC(NtBu)2]SnC≡CPPh2(3)、[HC(CMe)2(NAr)2]Sn C≡CPPh2(4)和[HC(CMe)2(NAr)2]ZnC≡CPPh2(5),研究了这些化合物与B(C6F5)3的反应.在与B(C6F5)3的反应中,1和2均发生1,1-碳硼化反应生成烯烃化合物(Ph)(Mes2HSi)C=C(C6F5)B(C6F5)2 (6)和{[tBuC(NAr)2]Ge}(Ph)C=C(C6F5)B(C6F5)2 (7), 7是一种GeⅡ/B松散Lewis酸碱对化合物;3~5则都发生B(C6F5)3与配体金属基的位置交换、进而配体金属基转换键合PPh2的反应,分别生成新颖的分子内双性离子炔烃化合物[PhC(NtBu)2]SnP(Ph2)C≡CB(C6F5)3 (8)、[HC(CMe)2(NAr)2]SnP(Ph2)C≡CB(C6F5)3(9)、[HC(CMe)2(NAr)2]ZnP(Ph2)C≡CB(C6F5)3 (10).文中还讨论了反应机理.

Synthesis of Alkynes Composed of the Novel Substituents and Their Reactions withB(C6F5)3

Five alkyne compounds of varied novel substituents as Mes2HSiC≡CPh(1, Mes=2,4,6-Me3C6H2), [tBuC-(NAr)2]GeC≡CPh(2, Ar=2,6-iPr2C6H3), [PhC(NtBu)2]SnC≡CPPh2(3), [HC(CMe)2(NAr)2]SnC≡CPPh2,(4) and [HC(CMe)2(NAr)2]ZnC≡CPPh2(5) have been synthesized. Compounds 1 and 2 reacted with B(C6F5)3 by the 1,1-carboboration to give compounds(Ph)(Mes2HSi)C=C(C6F5)B(C6F5)2(6) and {[tBuC(NAr)2]Ge}(Ph)C=C(C6F5)B(C6F5)2(7), respectively, where(F5C6)3 B/Mes2HSi group exchange was suggested to occur initially for the former reaction while the(F5C6)3 B/[tBuC(NAr)2]Ge exchange was for the latter one. Compound 6 is a acyclic alkene whereas 7 is viewed as a germanaboracyclobutene owing to a strong GeⅡ→B donor-acceptor bonding being a GeII/B frustrated Lewis pair(FLP). Compounds 3~5 reacted with B(C6F5)3 to undergo a ligand coordinated metal group/B(C6F5)3 exchange followed by bonding of metal group at PPh2, resulting in the formation of a novel type of intramolecular zwitterionic alkynes [PhC(NtBu)2]SnP(Ph2)C≡CB(C6F5)3(8), [HC(CMe)2(NAr)2]SnP(Ph2)C≡CB(C6F5)3(9), and [HC(CMe)2(NAr)2]ZnP(Ph2)C≡CB(C6F5)3(10), respectively. Compounds 1~10 have been characterized by spectroscopy and elemental analysis, of which 4, 6, 7, and 10 are further authenticated by X-ray crystallography. The mechanisms of these reactions are discussed.