T. Mukaiyama et al., Efficient method for pinacol coupling of aromatic and aliphatic ketones byusing titanium(II) chloride and zinc in the presence of pivalonitrile, CHEM LETT, (11), 1998, pp. 1107-1108
The reductive coupling reaction of aromatic and aliphatic ketones including
acyclic aliphatic ketones proceeded smoothly to give the corresponding pin
acols in good to high yields below room temperature by the combined use of
titanium(II) chloride and zinc in the presence of pivalonitrile. Meso-selec
tive formation of the coupling products was observed in the cases with some
acyclic aliphatic ketones.