Corey Stephenson and colleague at the University of Michigan have reported in JACS on the synthesis of pseudotabersonine. A mental roadblock for me was when I was looking at the paper, I was trying to find the structure of catalyst 5, which was the iridium catalyst used for a ring opening reaction, but just found the number 5 in the scheme. Within the text of the paper however it says Ir(dF(CF3)ppy)2(dtbbpy)PF6, which was cited with a Sigma Aldrich catalog number.
Matthew Gaunt and co-workers from the University of Cambridge have reported in Nature on a palladium catalyzed intramolecular C-N bond formation from C-H bonds. I am reminded of the ACIE paper from Frances Arnold’s group at Caltech where they used a P450 mutant to do a similar reaction.
When I saw the graphical abstract of this paper, the first thing that came to mind was Michael Kerr at the University of Western Ontario, but this paper was from Yong Tang’s group in SIOC in collaboration with Kendall Houk’s computational group to study the mechanism of this [3+2] reaction. They used the LANL2DZ basis set in this paper. Great to hear.
Juan Cuerva and co-workers from the University of Granada in Spain have reported in JACS on a titanocene mediated polyolefin cyclization reaction that studied with Gaussian calculations. The basis set used to approximate the titanocene catalyst was 6-31G*. From my little knowledge of Gaussian, when using QM calculations to study a reaction mechanism, you need two things: 1) the basis set and 2) the method. The basis set is the linear combination of a set of functions used to approximate the molecular orbitals. There are many kinds of basis sets that can be used for Gaussian. In my experience with transition metals however, I was unable to use the 6-31G* basis set because the transition metals have more complicated molecular orbitals since they have d-orbitals. I had to use the Los Alamos basis set: LANL2Dz. I eventually gave up on my time with Gaussian because I just kept running into problems and eventually had to focus my efforts into experimental work. But hopefully one day I can go back to this stuff again. Afterall, it helps us understand the reaction mechanisms better.