There are a number of papers that have described catalytic asymmetric C-H insertion reactions (see a recent review on catalytic intramolecular C-H aminations by Davies & Long), but there are only a few examples of asymmetric O-H insertion reactions. In the ASAP section of the Journal of the American Chemical Society, Maier & Fu reported the first “effective” method for catalytic enantioselective insertions into O-H bonds.

The authors showed that in the presence of copper and a chiral bisazaferrocene ligand, various alcohols reacted with methyl alpha-diazo-alpha-phenylacetate, yielding alpha-alkoxy esters (the best yields and ee were achieved using methanol, 2-trimethylsilylethanol, or para-methoxybenzyl alcohol). They further explored the scope of the reaction involving 2-trimethylsilylethanol and demonstrated that they could isolate a range of alpha-diazo-alpha-arylacetates in high yields and ee – since the trimethylsilylethyl group can be easily removed using boron trifluoride diethyl etherate, the authors could also obtain enantiomerically pure alpha-hydroxy esters in high yields and ee.

Joshua

Joshua Finkelstein (Associate Editor, Nature)

They’re worth a cool $57 billion to the United States each year, that’s what.

Next time you dismiss insects as mere creepy-crawlies, ponder for a while on what life would be like without them. Our six-legged friends might be more valuable than you think — research estimates that they’re worth at least a staggering $57 billion to the US economy every year.

Read the story here.