Formal [4+2] cycloaddition of cyclobutanones bearing alkyne–cobalt complex at their 3-positions

Mizuki Kawano, Takaaki Kiuchi, Jun-ichi Matsuo, Hiroyuki Ishibashi

Tetrahedron Letters
Volume 53, Issue 4, 25 January 2012, Pages 432–434

http://dx.doi.org/10.1016/j.tetlet.2011.11.067

PL