ketenes造句

• Another way to generate ketenes is through flash vacuum thermolysis with 2-pyridylamines.
• Diphenylketene, like most disubstituted ketenes, is a red-orange oil at room temperature and pressure.
• These highly electrophilic ketenes allow various chemical reactions to take place by reacting the unstable ketene with other chemicals.
• One such example is the preparation of ketenes which may employ a tube furnace in the'ketene lamp '.
• When ketenes are formed in the presence of alkynes they proceed through pericyclic reactions to generate a substituted aromatic ring ( Scheme 2 ).
• The silyloxyacetylenes are useful substitutes for alkoxyacetylenes in [ 2 + 2 ] cycloaddition reactions with ketenes and vinylketenes affording cyclobutenones ( Scheme 8 ).
• The reaction with sulfenes instead of ketenes leading to " ? "-sultams is called "'Sulfa-Staudinger cycloaddition " '.
• "' Thioketenes "'are organosulfur compounds analogous to ketenes with the general formula R 2 C = C = S, where R is alkyl or aryl.
• Pl黦 and Wentrup developed a method in 1997 that improved on FVT reactions to produce ketenes with a stable FVT that is moisture insensitive, using mild conditions ( 480 癈 ).
• :"'2-( trimethylsiliyl ) thiazole "'( with a trimethylsilyl group in the 2-position ) is a stable substitute and reacts with a range of electrophiles such as aldehydes, acyl halides, and ketenes
• CO Fixation to Stable Acyclic and Cyclic Alkyl Amino Carbenes : Stable Amino Ketenes with a Small HOMO-LUMO Gap V . Lavallo .; Y . Canac .; B . Donnadieu .; W . W . Schoeller .; G . Bertrand *.