Propargyl allene

If the addition involves an alkynyllithium such as 34, the first-formed alkoxide intermediate 35 isomerizes into the propargylic-allenic lithium reagent. Reactions with electrophiles lead to either 36a or the allenol silyl ethers 36b (equation 13). ... [Pg.465]

Treatment of 3-allyl-3-(2-propynyl)-2,4-pentanedione with methyl-hydrazine to give condensation and propargyl-allene rearrangement [118]. [Pg.278]

Mechanistically, this new insertion-CI-Diels-Alder hetero domino sequence can be rationalized as follows (Scheme 64) After the oxidative addition of the aryl halide 115 or 118 to the in situ generated Pd(0) species the arylpalladium halide 120 intramolecularly coordinates and inserts into the tethered triple bond via a syn-carbopaUadation to furnish cyclized vinylpalladium species 121 with a p-acceptor substitution in a stereospecific fashion. Transmetallation of the in situ generated copper acetylide 122 gives rise to the diorganylpalladium complex 123 that readily undergoes a reductive elimination and liberates the electron poor vinylpropargylallyl ether 124. The triethylamine catalyzed propargyl-allene isomerization furnishes the... [Pg.77]

Reactions of Ally I and Propargyl/Allenic Organometallics with Imines and Iminium Ions... [Pg.975]

Reactions ofAllyl and Propargyl/Allenic Organometallics with [mines and [minium [ons 981... [Pg.981]

Reactions ofAllyl and Propargyl/Allenic Organometallics with Imines and Iminium Ions 993 Table IS Reaction of Propargyl/Allenyl Organometallic Reagents (59) with Imines (60 Equation 14)... [Pg.993]

Table 27 Reaction of Propargyl/Allenic Organometallics (141) with gem-Amino Ethers (142 Equation 30) ...

Table 24 Reactions of Propargyl/Allenic Organometallic Reagents (117) with Iminium Salts (118 Equation 27)M...

The reaction of aldehydes or ketones proceed through the six-center electronic transfer with propargylic-allenic rearrangement [3]. [Pg.183]

Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...