196407-38-2

Upstream product

• 106180-32-9 2-Phenylethynyl-cyclohept-1-enecarbaldehyde 
• 536-74-3 phenylacetylene 
• 502-42-1 cycloheptanone 
• 85236-13-1 2-bromocyclohept-1-ene-1-carbaldehyde 

Relevant academic research and scientific papers

Gold-Catalyzed Oxidative Cyclizations of { o-(Alkynyl)phenyl propargyl} Silyl Ether Derivatives Involving 1,2-Enynyl Migration: Synthesis of Functionalized 1 H-Isochromenes and 2 H-Pyrans

A new and convenient strategy for the synthesis of functionalized 1H-isochromene and 2H-pyran derivatives based on gold-catalyzed oxidative cyclizations of o-(alkynyl)phenyl propargyl ether derivatives has been developed. The reaction proceeds via gold-catalyzed highly regioselective oxidation, followed by 1,2-migration of an enynyl group and nucleophlic addition. Isocoumarins were also constructed through oxidative cleavage of the exocyclic double bond of the obtained 1H-isochromenes.

Ring size effects in the C2-C6 biradical cyclisation of enyne-allenes and the relevance for neocarzinostatin

The regioselectivity of the thermal cyclisations of enyne-allenes 1 can be toggled as a function of the ring size of the cycloalkene. With a cyclopentene as the ene moiety the Myers-Saito (C2-C7) cycloaromatisation product is formed, whereas with six- and seven-membered cycloalkenes the novel C2-C6 cyclisation is observed. DFT calculations are used to rationalise these changes. The implications of these findings for alternative thermal biradical cyclisations of neocarzinostatin are discussed.

Ring strain effects in enyne-allene thermolysis: Switch from the Myers-Saito reaction to the C2-C6 biradical cyclization

The mode of the thermal cyclization of enyne-allenes 1 depends on ring strain effects: when the ene functionality is part of a benzene, cyclohexene or cycloheptene ring the novel C2-C6 biradical cyclization is observed, while when it is part of a cyclopentene ring the Myers-Saito cycloaromatization is registered.