نتایج جستجو برای: protecting group
تعداد نتایج: 1006342 فیلتر نتایج به سال:
We have combined the benefits of both microfluidics and flow hydrogenation to provide facile access to previously underutilized reduction and protecting group chemistries for PET imaging applications. The rapid removal of an O-benzyl protecting group to prepare 2-[(18)F]fluoroquinolin-8-ol and the reduction of a nitro group in the synthesis of 4-[(18)F]fluoroaniline were achieved within 3 minutes.
Despite significant advances in the last three decades towards high yielding syntheses of rotaxanes, the preparation of systems constructed from more than two components remains a challenge. Herein we build upon our previous report of an active template copper-catalyzed azide-alkyne cycloaddition (CuAAC) rotaxane synthesis with a diyne in which, following the formation of the first mechanical b...
We report an efficient, atom economical general acid-base catalyzed one-step multi-gram synthesis of azepinomycin from commercially available compounds in water. We propose that the described pH-dependent Amadori rearrangement, which couples an amino-imidazole and simple sugar, is of importance as a potential step toward predisposed purine nucleotide synthesis at the origins of life.
The protecting-group-free asymmetric synthesis of 1,2,4-trideoxy-1,4-imino-L-xylitol is readily achieved in five steps from 2-deoxy-D-ribose and with an overall yield of 48%. Key in this synthesis is the application of our recently developed Vasella-reductive amination and carbamate annulation methodologies to the synthesis of 2-deoxy-aza-sugars. The carbamate annulation occurred with excellent...
We report herein the design, preparation and first applications of novel trityl tags with adjustable stability, efficient as protecting groups or MS analytes.
Selective modification of electrode surfaces is a vital step in the development of many practical applications of self-assembled monolayers (SAMs). This paper describes a protection-deprotection strategy similar to that commonly utilized in organic synthesis, with gold oxide as a protecting layer, to direct self-assembly on one gold electrode in the presence of another.
The 9-phenyland the 9-(p-tolyl)-xanthen-9-yl groups 2a and 2b are recommended as alternatives to the 4,40-dimethoxytrityl group 1 for the protection of the 50-hydroxy functions in oligonucleotide synthesis. 2004 Elsevier Ltd. All rights reserved.
Tetrahydropyranyl (Thp) is recognized as a useful protecting group for alcohols in organic synthesis. It has several advantages, including low cost, ease of introduction, general stability to most non-acidic reagents, it confers good solubility, and the ease with which it can be removed if the functional group it protects requires manipulation. However, little attention has been paid to Thp in ...
Herein we report the first enantioselective total synthesis of (+)-dichroanone, confirming the absolute configuration of the natural product. This protecting group-free route features the first application of our enantioselective Tsuji allylation in the context of a natural product total synthesis. Additionally, this 11-step preparation of the molecule from commercial material features a novel ...
A 2-hydroxyphenacyl moiety absorbing below 370 nm is proposed as a new photoremovable protecting group for carboxylates and sulfonates. Laser flash photolysis and steady-state sensitization studies show that the leaving group is released from a short-lived triplet state. In addition, DFT-based quantum chemical calculations were performed to determine the key reaction steps. We found that triple...
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