Borylene-Based Direct Functionalization of Organic Substrates: Synthesis, Characterization, and Photophysical Properties of Novel pi-Conjugated Borirenes

作者：Braunschweig Holger^*; Herbst Thomas; Rais Daniela; Ghosh Sundargopal; Kupfer Thomas; Radacki Krzysztof; Crawford Andrew G; Ward Richard M; Marder Todd B; Fernandez Israel; Frenking Gernot

来源：Journal of the American Chemical Society, 2009, 131(25): 8989-8999.

DOI：10.1021/ja902198z

Room temperature photolysis of aminoborylene complexes, [(CO)(5)M=B=N(SiMe3)(2)] (1: M = Cr, 2: Mo) in the presence of a series of alkynes and diynes, 1,2-bis(4-methoxyphenyl)ethyne, 1,2-bis(4(trifluoromethyl)phenyl)ethyne, 1,4-diphenylbuta-1,3-diyne, 1,4-bis(4-methoxyphenyl)buta-1,3-diyne, 1,4-bis(trimethylsilylethynyl) benzene and 2,5-bis(4-N,N-dimethylaminophenylethynyl)thiophene led to the isolation of novel mono and bis-bis-(trimethylsilyl)aminoborirenes in high yields, that is [(RC=CR)(mu-BN(SiMe3)2], (3: R = C6H4-4-OMe and 4: R = C6H4-4-CFA [{(mu-BN(SiMe3)(2)(RC=C-)}(2)], (5: R = C6H5 and 6: R = C6H4-4-OMe); [1,4-bis-{(mu-BN(SiMe3)(2)(SiMe3C=C)}benzene], 7 and [2,5-bis-{(mu-BN(SiMe3)(2) ((C6H4NMe2)-C=C)}-thiophene], 8. All borirenes were isolated as light yellow, air and moisture sensitive solids. The new borirenes have been characterized in solution by H-1, B-11, C-13 NMR spectroscopy and elemental analysis and the structural types were unequivocally established by crystallographic analysis of compounds 6 and 7. DFT calculations were performed to evaluate the extent of pi-conjugation between the electrons of the carbon backbone and the empty p, orbital of the boron atom, and TD-DFT calculations were carried out to examine the nature of the electronic transitions.

• 出版日期2009-7-1