Examination of nature's favorite molecules reveals a striking preference for making carbon-heteroatom bonds over carbon-carbon bonds-surely no surprise given that carbon dioxide is nature's starting material and that most reactions are performed in water. Nucleic acids, proteins, and polysaccharides are condensation polymers of small subunits stitched together by carbon-heteroatom bonds. Even the 35 or so building blocks from which these crucial molecules are made each contain, at most, six contiguous C-C bonds, except for the three aromatic amino acids. Taking our cue from nature's approach, we address here the development of a set of powerful, highly reliable, and selective reactions for the rapid synthesis of useful new compounds and combinatorial libraries through heteroatom links (C-X-C), an approach we call "click chemistry". Click chemistry is at once defined, enabled, and constrained by a handful of nearly perfect "spring-loaded" reactions. The stringent criteria for a process to earn click chemistry status are described along with examples of the molecular frameworks that are easily made using this spartan, but powerful, synthetic strategy.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/1521-3773%2820010601%2940%3A11%3C2004%3A%3AAID-ANIE2004%3E3.0.CO%3B2-5

Click Chemistry: Diverse Chemical Function from a Few Good Reactions.

Betrachtet man die in der Natur am haufigsten vorkommenden Verbindungen, so fallt auf, dass die Bildung von Kohlenstoff-Heteroatom-Bindungen gegenuber der von Kohlenstoff-Kohlenstoff-Bindungen deutlich bevorzugt ist Da zum einen Kohlendioxid die Basisverbindung der Natur ist und andererseits das Medium naturlicher Reaktionen zumeist Wasser ist, uberrascht dies sicherlich nicht Nucleinsauren, Proteine und Polysaccharide sind polymere Kondensationsprodukte kleiner Untereinheiten, die durch Kohlenstoff-Heteroatom-Bindungen verknupft sind Sogar die etwa 35 Baueinheiten, aus denen diese essentiellen Verbindungen bestehen, enthalten nicht mehr als sechs aufeinander folgende C-C-Bindungen, sieht man einmal von den drei aromatischen Aminosauren ab Mit der Natur als Vorbild richteten wir unser Interesse auf die Entwicklung leistungsfahiger, gut funktionierender und selektiver Reaktionen fur die effiziente Synthese neuartiger nutzlicher Verbindungen sowie kombinatorischer Bibliotheken mittels Heteroatomverknupfungen (C-X-C) Diese Synthesestrategie nennen wir „Click-Chemie“ Click-Chemie ist durch eine Auswahl einiger weniger nahezu idealer Reaktionen charakterisiert, mit all ihren Grenzen und Moglichkeiten In diesem Beitrag werden zum einen die strengen Kriterien, die Reaktionen erfullen mussen, um die Bezeichnung „Click-Chemie“ zu verdienen, definiert, zum anderen werden Beispiele fur molekulare Strukturen gegeben, die mit dieser spartanischen, aber dennoch leistungsfahigen Synthesestrategie leicht hergestellt werden konnen

Click-Chemie: diverse chemische Funktionalität mit einer Handvoll guter Reaktionen

Claisen rearrangement over the past nine decades.

Recent developments in the stereoselective synthesis of α-aminoacids

(1990). The Shikimate Pathway — A Metabolic Tree with Many Branche. Critical Reviews in Biochemistry and Molecular Biology: Vol. 25, No. 5, pp. 307-384.

The shikimate pathway―a metabolic tree with many branches

Isopropylidenation of 1,2-O-cyclohexylidene-myo-inositol and its 3-O-tosyl- and 3-O-benzoyl derivatives with 2,2-dimethoxypropane in N,N-dimethylformamide in the presence of acid catalyst gave the corresponding 4,5- and 5,6-O-isopropylidene derivatives. Selective benzoylation of 1,2-O-cyclohexylidene-4,5-O-isopropylidene-myo-inositol with benzoyl chloride in pyridine gave mainly the 3-O-benzoate, whereas with benzoic anhydride the 6-O-benzoate. Several unaccessible blocked inositols were prepared by displacement reaction of the protected sulfonyl derivatives with sodium benzoate.

Inositol derivatives. 10. isopropylidenation of 1,2-o-cyclohexylidene-myo-inositol derivatives and preparation of unaccessible blocked inositols

The structure of the title compound, C6H10O6, was determined to confirm the position of the keto group in the mol­ecule prepared enantioselectively by a bioconversion from myo-inositol. There are two independent mol­ecules showing similar geometry.

(–)‐epi‐Inosose‐2

Synthesis of pseudo-oligosaccharidic glycosidase inhibitors, part ii. synthesis of amylostatin (xg)

Pseudosugars. Part 40. Synthesis of Ether- and Imino-Linked Octyl N-Acetyl-5a′-carba-β-lactosaminides and -isolactosaminides: Acceptor Substrates for α-(1→3/4)-Fucosyltransferase, and Enzymatic Synthesis of 5a′-Carbatrisaccharides.

Pseudosugars. Part 43. Synthesis of Building Blocks for Carba‐oligosaccharides: 5a′‐Carbamaltose and 5a′‐Carbacellobiose, and 5a‐Carba‐β‐D‐mannopyranosyl‐(1→4)‐D‐glucopyranose.

Seiichiro Ogawa

Papers

Inositol derivatives. 10. isopropylidenation of 1,2-o-cyclohexylidene-myo-inositol derivatives and preparation of unaccessible blocked inositols

(–)‐epi‐Inosose‐2

Synthesis of pseudo-oligosaccharidic glycosidase inhibitors, part ii. synthesis of amylostatin (xg)

Pseudosugars. Part 40. Synthesis of Ether- and Imino-Linked Octyl N-Acetyl-5a′-carba-β-lactosaminides and -isolactosaminides: Acceptor Substrates for α-(1→3/4)-Fucosyltransferase, and Enzymatic Synthesis of 5a′-Carbatrisaccharides.

Pseudosugars. Part 43. Synthesis of Building Blocks for Carba‐oligosaccharides: 5a′‐Carbamaltose and 5a′‐Carbacellobiose, and 5a‐Carba‐β‐D‐mannopyranosyl‐(1→4)‐D‐glucopyranose.