38159-72-7

Upstream product

• 1499-10-1 9,10-diphenylanthracene 
• 3623-15-2 phenyl propargyl ketone 
• 38159-73-8 (9,10-diphenyl-[2]anthryl)-phenyl ketone 

Relevant academic research and scientific papers

Reactivity of the 16-electron CpCo half-sandwich complex containing a B(3,6)-disubstituted o-carborane-1,2-dithiolate ligand

The 16-electron (16e) half-sandwich complex CpCo(S2C 2B10H8)(CHCHCO2Me)2 (1; Cp = cyclopentadienyl) was considered as inert owing to hindered di-substitution at B sites. However in methanol complex 1 reacts with ethynylferrocene (FcCCH) and dimethyl acetylenedicarboxylate (DMAD, MeO2CCCCO2Me) to lead to two-fold alkyne insertion at Co-S bond to give rise to unusual stable 18e adduct CpCo(S2C2B10H8) (CHCHCO2Me)2(HCCFc)(MeO2CCCCO2Me) (2) containing mixed alkynes. Also in methanol complex 1 undergoes intramolecular hydrogen transfer of one CHCHCO2Me unit to adjacent carbon to form a CH2CCO2Me unit, thus producing the 18e complex CpCo(S2C2B10H8)[CH 2CCO2Me][CHCHCO2Me] (3). Further investigation indicates that complex 1 can catalyze [2 + 2 + 2] cycloaddition of alkynes. The catalytic efficiency is determined by temperature and nature of alkynes. In THF in the presence of [N(n-Bu)4]Br complex 1 is transformed to ionic complex [N(n-Bu)4]+[Co(S2C2B 10H8)2(CHCHCO2Me)4] - (4), in which metal-dithiolene is planar. Analogous [N(n-Bu) 4]+[Co(S2C2B10H 9)2(CHCHCO2Me)2]- (5) was also synthesized from mono-substituted precursor CpCo(S2C 2B10H9)(CHCHCO2Me) (1′). The electrochemical properties of both 4 and 5 show significant positive shift of redox peaks versus the analogous bis(1,2-benzenedithiolato)cobaltate (III) (Co(bdt)2). Reactivity of both neutral 16e CpCo complexes and ionic metal-dithiolene derivatives declines with the increase of substituents on carborane cage. All the new compounds have been characterized by NMR, IR, mass spectrometry, elemental analysis, and 2, 3, and 4 have been structurally characterized by X-ray diffraction.

Iron-catalyzed trimerization of terminal alkynes enabled by pyrimidinediimine ligands: A regioselective method for the synthesis of 1,3,5-substituted arenes

The development of pyrimidine-based analogues of the well-known pyridinediimine (PDI) iron complexes enables access to a functional-group-tolerant methodology for the catalytic trimerization of terminal aliphatic alkynes. Remarkably, in contrast to established alkyne trimerization protocols, the 1,3,5-substituted arenes are the main reaction products. Preliminary mechanistic investigations suggest that the enhanced π-acidity of the pyrimidine ring, combined with the hemilability of the imine groups coordinated to the iron center, facilitates this transformation. The entry point in the catalytic cycle is an isolable iron dinitrogen complex. The catalytic reaction proceeds via a 1,3-substituted metallacycle, which explains the observed 1,3,5-regioselectivity. Such a metallacycle could be isolated and represents a rare 1,3-substituted ferracycle obtained through alkyne cycloaddition.