Alkyne-esters, from

Alkynes from halides also alkynes from alkynes Esters from alcohols also esters from carboxylic acids Alkyls from alkenes (Conjugate Reduction)... 

No intennolecular reaction of malonate or /3-keto esters with halides has been reported, but the intramolecular reaction of /3-diketones such as 790 and malonates proceeds smoothly[652,653]. Even the simple ketone 791 can be arylated or alkenylated intramolecularly. In this reaction, slow addition of a base is important to prevent alkyne formation from the vinyl iodide by elim-ination[654]. 

Scheme 17 Preparation of (Z)-chloroacrylate esters from terminal alkynes...

Such reactions occur readily with alkynic esters, but the products isolated are often complex. Thus, the initial Michael adduct of type (68) from pyridine with acetylenedicarboxylic ester reacts with more alkynic ester to yield (66), (67) and other products. Quinoline and isoquinoline react similarly. 

One of the characteristic reactions of the Ti reagent is the intramolecular nucleophilic acylation of the titanacycle with esters, and 2,7- and 2,8-enyne esters afford interesting mono- and bicyclic skeletons [125], Titanacycle 297, formed from a, /i-unsaturated ester 296, is converted to the alkenyltitanium 300 by protonation, and the cyclopentenone 301 is formed by intramolecular acylation [126], As 297 is a tautomeric form of the Ti enolate, it reacts with electrophiles such as aldehydes to give 298, which cyclizes to 299. The a,/i-alkynic ester 302 generates the titanacycle 303 and is converted to the bicyclo[3.1.0]hexane system 305 via 304 [126]. The titanacycle... 

Scheme 4. Preparation of enol esters and dienyl esters from terminal alkynes and carboxylic acids.

The reaction was applied to the formation of arylcopper used for homocoupling and coupling reactions, which have already been described in Section IV.B.2. In addition, it was established that the simple use of copper(I) salts in polar solvents permitted the transmetallation from tin to copper. The transient vinylcopper reagent was subjected to various intramolecular reactions such as coupling with vinyl halides , addition to a, /S-unsaturated ketones , to a, /3-unsaturated esters and addition to a, /3-alkynic esters . In addition to copper(I) halides, the reaction can be mediated by copper(I) cyanide and... 

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