Removal of Silyl Ether Protecting Groups
Reaction with acids or fluorides such as tetra-n-butylammonium fluoride remove the silyl group when protection is no longer needed. Larger substituents increase resistance to hydrolysis, but also make introduction of the silyl group more difficult.
In acidic media, the relative stability is:
- TMS (1) < TES (64) < TBS (20 000) < TIPS (700 000) < TBDPS (5 000 000)
In basic media, the relative stability is:
- TMS (1) < TES (10-100) < TBS~TBDPS (20 000) < TIPS (100 000)
Read more about this topic: Silyl Ether
Famous quotes containing the words removal of, removal, ether, protecting and/or groups:
“Anyone who seeks for the true causes of miracles, and strives to understand natural phenomena as an intelligent being, and not to gaze at them like a fool, is set down and denounced as an impious heretic by those, whom the masses adore as the interpreters of nature and the gods. Such persons know that, with the removal of ignorance, the wonder which forms their only available means for proving and preserving their authority would vanish also.”
—Baruch (Benedict)
“If God now wills the removal of a great wrong, and wills also that we of the North as well as you of the South, shall pay fairly for our complicity in that wrong, impartial history will find therein new cause to attest and revere the justice and goodness of God.”
—Abraham Lincoln (1809–1865)
“Is this then a touch? quivering me to a new identity,
Flames and ether making a rush for my veins,
Treacherous tip of me reaching and crowding to help them,
My flesh and blood playing out lightning to strike what is hardly
different from myself,
On all sides prurient provokers stiffening my limbs,”
—Walt Whitman (1819–1892)
“The duty of government is to leave commerce to its own capital and credit as well as all other branches of business, protecting all in their legal pursuits, granting exclusive privileges to none.”
—Andrew Jackson (1767–1845)
“Some of the greatest and most lasting effects of genuine oratory have gone forth from secluded lecture desks into the hearts of quiet groups of students.”
—Woodrow Wilson (1856–1924)