Carbon−Carbon Bond Formation and Cleavage in the Dimerization of a Nickelacycle
作者:T. V. V. Ramakrishna、Paul R. Sharp
DOI:10.1021/om0497590
日期:2004.6.1
L2NiCl2 (L = PEt3) gives the nickelacycle L2Ni(1,12-triphenylenediyl), which decomposes to a dimer (L2Ni2C36H20) containing two coupled triphenylene moieties with a new C−C bond. Thermolysis of the dimer completes the coupling, yielding a chiral tetraphenylene, while alkyne addition leads to cleavage of the newly formed C−C bond of the dimer and cycloaddition of the alkyne to the triphenylene fragment
Autocatalytic Alkyne Cycloadditions: Evidence for Colloidal Pt Catalysis
作者:Rowshan Ara Begum、Nripen Chanda、T. V. V. Ramakrishna、Paul R. Sharp
DOI:10.1021/ja054863+
日期:2005.10.1
Treatment of the four-membered platinacycle L2Pt(1,8-naphthalendiyl) (1) or the five-membered platinacycle L2Pt(1,12-triphenylendiyl) with excess PhCCPh at 120-150 degrees C gives the coupling products 1,2-diphenylacenaphthalene or 4,5-diphenylbenzo[e]pyrene and the alkyne complex L2Pt(eta2-PhCCPh). Both reactions show an accelerating rate, which has been traced to catalysis of the reaction by colloidal platinum formed by the reaction of O2 with L2Pt(eta2-PhCCPh).