Tuesday, August 6, 2013

CPME? New to Me!

While reading through the latest Org. Lett. ASAPs, I came across a slick cross-coupling reported by the Walsh group (UPenn). The reaction unites acetamides and aryl chlorides, helped along by a "hybrid" Buchwald-Kwong pre-catalyst. Neat stuff.

Source: Org. Lett. | Walsh group

A certain passage caught my eye, midway down the second page (emphasis mine):
 "...four common solvents [toluene, cyclopentyl methyl ether (CPME), dioxane, and dimethoxyethane (DME)] were screened..."
All 'common' solvents, even CPME? I don't recall seeing that solvent in Trevor Laird's OPRD piece. Or on several solvent boiling point charts. In fact, I don't think I've ever used it...and I'm doing cross-couplings all day!

A quick literature dig on CPME turned up this OPRD, perhaps its grand introduction to the process scene. Looks like it exhibits several advantages over diethyl ether (higher boiling, lower peroxide formation), and improved safety metrics over dioxane or THF.

Readers: Am I just late to the game? Are process folks everywhere charging liters of CPME into reactors 24/7? Please clue me in.


  1. See Arr Oh:

    This comment on In The Pipeline mentioned it. I don't know if Aldrich had advertised it before, as well.

  2. Having interned at Merck Process, I can't recall having used CPME there. I was always encouraged to use methyl tert-butyl ether, aka MTBE. Granted, that was back in 2006... I have since gone through grad school and much has probably changed.