Four Mechanistic Mysteries: The Benefits of Writing a Critical Review.

While writing a comprehensive review on the reactions of epoxides with titanium(III) reagents, we encountered a series of mechanistic puzzles. Using clues from the literature, many of which were not available at the time that the mysteries emerged, it was possible to demystify a number of these conundrums. We discuss four examples, which we believe will significantly change the way in which titanium(III) chemistry is practiced. Our experience underscores the importance of comprehensive and critical reviews in chemistry and the truism that the authors are prime beneficiaries of the review process.