Yeah, BBr3 is nasty. I wrap it into foil, put in plastic container and seal slits with parafilm - so that it can peacefully coexist with other bottles in a dessicator not covering everything with white dust.
BBr3 I loath to work with even more than Br2. Btw, what is BCl3 solution useful for - is it actually for ArOMe deprotection, or perhaps Friedel-Craft?
Reminds me: A cleanup is EJC attic storeroom was memorable: First a giant safety officer named Littleboy knocked down a liter of TiCl4 and came down running the stairwell chased by a giant white plume, then an old over-pressurized bottle of iPrOCOCl blew up during the cleanup, and finally someone spilled hydrocinnamaldehyde in the freezer room, which made everyone participating in the cleanup smell like wearing a cheap loud aftershave
You know, I honestly don't know what that bottle of BCl3 was used for... I've been here 4 years and can't remember anyone telling me they used it - that doesn't mean someone didn't use it without telling me, of course ;)
Off the top of my head, Noah Burns did do a BBr3 deprotection during the synthesis of haouamine, maybe it was screened then, but that was years ago, before my time.
Let's not forget the 10 or so liters of THF and ether tragically lost to peroxide test strips.
ReplyDeleteYeah, BBr3 is nasty. I wrap it into foil, put in plastic container and seal slits with parafilm - so that it can peacefully coexist with other bottles in a dessicator not covering everything with white dust.
ReplyDeleteBBr3 I loath to work with even more than Br2. Btw, what is BCl3 solution useful for - is it actually for ArOMe deprotection, or perhaps Friedel-Craft?
ReplyDeleteReminds me: A cleanup is EJC attic storeroom was memorable: First a giant safety officer named Littleboy knocked down a liter of TiCl4 and came down running the stairwell chased by a giant white plume, then an old over-pressurized bottle of iPrOCOCl blew up during the cleanup, and finally someone spilled hydrocinnamaldehyde in the freezer room, which made everyone participating in the cleanup smell like wearing a cheap loud aftershave
You know, I honestly don't know what that bottle of BCl3 was used for... I've been here 4 years and can't remember anyone telling me they used it - that doesn't mean someone didn't use it without telling me, of course ;)
DeleteOff the top of my head, Noah Burns did do a BBr3 deprotection during the synthesis of haouamine, maybe it was screened then, but that was years ago, before my time.
As far as I remember, you can't take off ArOMe with BCl3, but you can remove ArOiPr.
DeleteFor the methoxy you need the more potent BBr3.
It's a little protecting group trick that was recently used in Beaudry's total synthesis of Cavicularin (OL 2013 pp402-405).
We used it in the meroterpenoid paper. It was used to open up chromazonarol to zonarol/isozonarol.
ReplyDeleteThank you for reminding me of that boronic-terpene paper; it was a particularly sweet way of making cyclized oligoprenoids.
Delete