bear SiH and SiOR2 groups on the same siliconatom, R13Si–O–SiR32−n(OR2)nH (n = 0, 1, or 2), via a simple catalyst- and additive-free dealcoholization reaction between silanols and alkoxyhydrosilanes has been developed. These alkoxyhydrosiloxanes can be easily converted into Si(OR2)3-containing siloxanes by zinc catalyzed alkoxylation and alkoxy-containing silphenylene polymers by platinum catalyzed
O2 acts as a nonconsumed activator for gold nanoparticles (AuNPs) in the oxidation of hydrosilanes to silanols with water under O2 atmosphere, providing an acceleration of more than 200 times relative to the reaction rate under Ar atmosphere. The AuNP catalyst under aerobic conditions exhibits high activity in the oxidation with high turnover numbers (1230000). Various hydrosilanes including less-reactive bulky ones can be converted to the corresponding silanols in excellent yields. Moreover, the present AuNP catalyst is reusable while maintaining the high performance.
C−C Bond Formation via C−H Bond Activation: Catalytic Arylation and Alkenylation of Alkane Segments
作者:Bengü Sezen、Roberto Franz、Dalibor Sames
DOI:10.1021/ja027891q
日期:2002.11.1
A new system for catalyticarylation and alkenylation of alkanesegments has been developed. The ortho-tert-butylaniline substrates and 2-pivaloylpyridine may be arylated and alkenylated at the tert-butyl group, while no functionalization occurred at more reactive C-H and other bonds. Arylation and alkenylation of these substrates are achieved in the presence of Ph2Si(OH)Me and Ph-CH=CH-Si(OH)Me2,
Aggressive forms of adult T-cell leukemia (ATL) respond poorly to conventional anticancer chemotherapy, and new lead compounds are required for the development of drugs to treat this fatal disease. Recently, we developed ATL cell-selective proliferation inhibitors based on a tetrahydrotetramethylnaphthalene (TMN) skeleton 1, and here we report the design and synthesis of silicon analogs of TMN derivatives. Among them, compound 13 showed the most potent growth-inhibitory activity towards the ATL cell line S1T, though its selectivity for S1T over the non-ATL cell line MOLT-4 was only moderate. This result, as well as computational studies, suggests that sila-substitution (C/Si exchange) is useful for structure optimization of these inhibitors.