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US 5,124,448 AGranted
Deblocking process for allyl esters with regeneratable polymer supported Pd(O)
AssigneeMerck & Co., Inc.
InventorsDavid M. Tschaen, F. Edward Roberts, Thomas R. Verhoeven
Life of this patent
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Abstract
A regeneratable polymer-supported Pd(O) catalytic deblocking process using a regeneratable polymer-supported Pd(O) catalyst in a biphasic system deblocks various allyl-protected ester, carbonates, carbamates and cinnamyl esters.
Claims12
A method of deblocking an allylester, allyl carbonate, allyl carbamate or cinnamyl ester protecting group comprising the procedure of:
- reacting a compound having one or more said protecting groups, with a catalytic quantity of an organic insoluble polymer supported Pd(0) in a suitable organic solvent for said compound and in the presence of a nucleophile selected from the group consisting of 1,3-cyclopentanedione, 2-methyl-1,3-cyclopentanedione, 2-methyl-1,3-cyclohexanedione, potassium 2-ethylhexanoate and N-methyl morpholine, whereby said compound is deblocked;
- separating the reacted polymer supported Pd(0) from said deblocked compound:
- and
- regenerating the reacted polymer supported Pd(0) by reaction with more than one equivalent of a reducing agent in aqueous solution, where said reducing agent is NaBH.sub.4.
1 more element
A method of deblocking a protecting group with organic insoluble polymer supported Pd(0), and then regenerating the polymer supported Pd(0), comprising the steps of:
- (a) providing an equivalent of a compound having one or more protecting groups to be removed, said compound dissolved in an organic non-hydroxylic solvent, said protecting group selected from the group consisting of an allyl ester, allyl carbonate, allyl carbamate and cinnamyl ester;
- (b) adding about one equivalent of a necleophile;
- (c) mixing with about one equivalent of a polymer supported Pd(0) to yield deblocked compound and reacted polymer supported Pd(0);
- (d) separating the reacted polymer supported Pd(0) from deblocked compound;
- and
- (e) regenerating the reacted polymer supported Pd(0) by reaction with more than one equivalent of a reducing agent in aqueous solution.
3 more elements
Dependencies are inferred from the claim text.