In an approach toward a photochemically bistable molecular rotor the synthesis of cis-1a and trans1b isomers of 2-(2,6-dimethylphenyl)-9-(2′,3′-dihydro-1′H-naphtho[2,1-b]thiopyran-1′-ylidene)-9Hthioxanthene (1), being sterically overcrowded alkenes functionalized with an o-xylyl group as a rotor, is described. The key steps in the synthesis are a Suzuki coupling to attach the xylyl moiety and a...

Diazo transfer adjacent to a sulfoxide moiety to provide stable, isolable α-diazo-β-oxo sulfoxides has been achieved. Use of monocyclic and bicyclic sulfoxide precursors is critical in enabling isolation of stable derivatives, through introduction of conformational constraint, while acyclic α-diazo-β-oxo sulfoxides are too labile to isolate and characterize.

Diazo ketones derived from N-p-tolylsulfonyl (tosyl)-protected áand â-amino acids have been synthesized and their diazo decomposition under standard Wolff rearrangement conditions, PhCO2Ag–Et3N–MeOH, has been investigated. It is observed that, under these conditions, several different reaction pathways, including direct carbene N]H insertion, are possible. The reaction is markedly affected by t...

An investigation of the intramolecular cyclopropanation reactions of α-diazo-β-ketonitriles is reported. These studies reveal that α-diazo-β-ketonitriles exhibit unique reactivity in their ability to undergo arene cyclopropanation reactions; other similar acceptor-acceptor-substituted diazo substrates instead produce mixtures of C-H insertion and dimerization products. α-Diazo-β-ketonitriles al...

Heat and shock sensitive tosyl azide was generated and used on demand in a telescoped diazo transfer process. Small quantities of tosyl azide were accessed in a 'one pot' batch procedure using shelf stable, readily available reagents. For large scale diazo transfer reactions tosyl azide was generated and used in a telescoped flow process, to mitigate the risks associated with handling potential...

A two-stage "tandem strategy" for the regiocontrolled synthesis of very highly substituted quinolines is described. Benzannulation based on the reaction of cyclobutenones or diazo ketones with N-propargyl-substituted ynamides proceeds via a cascade of several pericyclic reactions to generate multiply substituted aniline derivatives. In the second stage of the tandem strategy, triflate derivativ...

The title compound, C(10)H(6)ClF(3)N(2)O(2), was synthesized by coupling 4-dimethyl-amino-1,1,1-trifluoro-but-3-en-2-one with 4-chloro-benzene-diazo-nium chloride. It crystallizes with two mol-ecules in the asymmetric unit, which form two similar centrosymmetric dimers via hydrogen bonds. Extensive electron delocalization and intra-molecular N-H⋯O hydrogen bonds are responsible for a planar con...

Abstract The synthesis of substituted isoxazole–oxazole hybrids by the noncatalytic reaction methyl 2-diazo-2-(alkyl/aryl/hetarylisoxazol-5-yl)acetates with alkyl and aryl cyanides has been reported. According to DFT calculations, proceeds through intermediate formation a nitrile ylide its subsequent cyclization at carbonyl oxygen. acrylonitrile 2-diazo-2-(isoxazol-5-yl)acetate quite differentl...

The diazo group has untapped utility in chemical biology. The tolerance of stabilized diazo groups to cellular metabolism is comparable to that of azido groups. However, chemoselectivity has been elusive, as both groups undergo 1,3-dipolar cycloadditions with strained alkynes. Removing strain and tuning dipolarophile electronics yields diazo group selective 1,3-dipolar cycloadditions that can b...