- Visible-Light-Mediated Oxidative Debenzylation Enables the Use of Benzyl Ethers as Temporary Protecting Groups
-
The cleavage of benzyl ethers by catalytic hydrogenolysis or Birch reduction suffers from poor functional group compatibility and limits their use as a protecting group. The visible-light-mediated debenzylation disclosed here renders benzyl ethers temporary protective groups, enabling new orthogonal protection strategies. Using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as a stoichiometric or catalytic photooxidant, benzyl ethers can be cleaved in the presence of azides, alkenes, and alkynes. The reaction time can be reduced from hours to minutes in continuous flow.
- Cavedon, Cristian,Sletten, Eric T.,Madani, Amiera,Niemeyer, Olaf,Seeberger, Peter H.,Pieber, Bartholom?us
-
supporting information
p. 514 - 518
(2021/01/26)
-
- Regioselective C-3-O-acylation and O-methylation of 4,6-O-benzylidene-β-D-gluco- and galactopyranosides displaying a range of anomeric substituents
-
The regioselective C-3-O-acylation and O-methylation of a range of 4,6-O-benzylidene-β-D-gluco- and galactopyranosides has been studied. Regioselectivity is achieved by forming the copper chelate of the 2,3-diol using either sodium hydride and copper(II) chloride, or copper(II) acetylacetanoate, or copper(II) acetate, prior to introduction of the acylating or methylating agent.
- Osborn, Helen M.I.,Brome, Victoria A.,Harwood, Laurence M.,Suthers, William G.
-
p. 157 - 166
(2007/10/03)
-
- Regioselective C-3-O-acylation and O-alkylation of 4,6-O-benzylidene-β-D-glucopyranoside derivatives displaying a range of anomeric substituents
-
Regioselective C-3-O-acylation and O-alkylation of ethyl 4,6-O-benzylidene-1-thio-β-D-glucopyranoside, phenyl 4,6-O-benzylidene-β-D-glucopyranoside and phenyl 4,6-O-benzylidene-1-seleno-β-D-glucopyranoside is described. Regioselectivity is obtained by first treating the benzylidene diols with sodium hydride and copper (II) chloride to form a THF soluble copper chelate.
- Gridley, Jonathan J.,Osborn, Helen M.I.,Suthers, William G.
-
p. 6991 - 6994
(2007/10/03)
-
- Total synthesis of tricolorin A
-
Tricolorin A (1), a structurally amazing resin glycoside with promising bioactivities from Ipomoea tricolor cav. (convolvulaceae), was synthesized in a total of 45 steps, with the longest linear sequence of 20 steps and overall yield of 0.65% from D-mannitol. The AB disscharide 19-membered lactone 2 was constructured by a regioselective macrolactonization using Corey-Nicolaou protocol. The macrolactone tetrasaccharide 33 was realized either by 'one- pot two-step' glycosylation procedure or by a stepwise assembly employing the 'armed-disarmed' glycosylation strategy.
- Lu, Shou-Fu,O'Yang, QinQin,Guo, Zhong-Wu,Yu, Biao,Hui, Yong-Zheng
-
p. 8400 - 8405
(2007/10/03)
-
- The First Total Synthesis of Tricolorin A
-
Keywords: glycosylations; macrocycles; one-pot reactions; total synthesis; tricolorin A
- Lu, Shou-Fu,O'yang, QinQin,Guo, Zhong-Wu,Yu, Biao,Hui, Yong-Zheng
-
p. 2344 - 2346
(2007/10/03)
-