124481-51-2

Upstream product

• 26327-98-0 (Z)-2,2,7,7-tetramethyl-3,6-dioxa-2,7-disilaoct-4-ene 
• 21572-32-7 2-chloro-1-phenyl-ethanone oxime 
• 6039-89-0 1,2-bis(trimethylsiloxy)ethene 

Downstream Products

• 1243250-53-4 N-tert-butoxycarbonyl-4-hydroxy-2-phenylpyrrolidine 
• 1243250-52-3 N-tert-butoxycarbonyl-2-phenyl-4-(trimethylsiloxy)pyrrolidine 
• 913642-44-1 N-tert-butoxycarbonyl-1-amino-4-phenyl-2-butanol 

Relevant academic research and scientific papers

On the Mechanism of Diels-Alder Reactions of Nitroso Alkenes: exo/endo Selectivity, Stereospecificity, E/Z Selectivity, and Relative Reactivity of Various Olefins

The mechanism of the hetero Diels-Alder reaction of nitroso alkenes 2 with silyl enol ethers and other olefins has been investigated.Using the bicyclic nitroso compound 2a a study of the exo/endo selectivity has demonstrated that the exo approach is preferred with the siloxyethene 1a as dienophile.On the other hand, the siloxycyclopentene 1c gives a mixture of cycloadducts 3c with an excess of endo product (endo:exo = 82:18).The stereospecificity of the nitroso alkene cycloaddition could be demonstrated with the stereochemically homogeneous silyl enol ethers 1b and 1d.Experiments with enol ethers 1f and 1g also occur stereospecifically. α-Nitrosostyrene 2b reveals surprisingly high kE/Z values when E/Z-isomeric olefins are compared in competition experiments.Also, a detailed reactivity scale of 2b including various structurally different silyl enol ethers and other typical dienophiles shows that a complex interplay of electronic and steric effects is operating.The large influence of steric effects is taken as evidence for a highly ordered transition state in the cycloaddition.All mechanistic details for the Diels-Alder reactions of nitroso alkenes 2 with (silyl) enol ethers are in strong accord with a concerted mechanism and exclude the involvement of zwitterions or diradicals as intermediates.

Synthesis of Trialkylsiloxy-Substituted and other 5,6-Dihydro-4H-1,2-oxazines by Hetero Diels-Alder Reactions of Nitroso Alkenes - Preparative Scope and Diastereoselectivity

A variety of 5,6-dihydro-4H-1,2-oxazines 3 and 4 is prepared in good yields from silyl enol ethers 1 and nitroso alkenes 2a or 2b, respectively.A systematic variation of substitutens reveals preparative scope and limitations of this hetero Diels-Alder rea