Copper phenylacetylide, reaction with

Another interesting cascade involving nitrones is the copper catalyzed reaction with alkynes to produce p-lactams that was originally reported by Kinugasa (72CC466). Stoichiometric amounts of copper(I) phenylacetylide (61) react with various aryl nitrones 62 in pyridine to give p-lactams 63 in 50-60% yield (equation (2)). In each case, only the czs-lactams were isolated. 

In the heterocyclization reactions of 4-acetylenyl-l-methylpyrazole-3-carbox-ylic acids and 4-acetylenyl-l-methylpyrazole-5-carboxylic acids the behavior is the same. Isomeric I-methyI-4-phenyIethynyIpyrazole-3-carboxylic acid forms 3 -lactones, 2-methyl-7-oxo-5-phenylpyrano[3,4-c]pyrazole, in 71 % yield (20 min) (Scheme 122). The same ester is obtained by acetylenic condensation (3 h) of 4-iodo-l-methylpyrazole-3-carboxylic acid with copper phenylacetylide. 

In 1972, Kinugasa and Hashimoto (841) reported the reaction of copper (I) phenylacetylide with a.A-diphenylnitrone in dry pyridine. It has provided an... 

Copper(I) phenylacetylide, C6H5C=CCu (1). The bright yellow reagent is prepared by reaction of phenylacetylene with 1 equiv. of Cul in aqueous ammonia (77% yield).1... 

Although the stoichiometric ethynylation of (47) with copper(I) phenylacetylide gives the product (48) of a normal double ethynylation, die Pd-catalyzed coupling reaction affords the fluorene derivative (49) instead. The reaction leading to (49) can be rationalized as proceeding via the a-fluorenyl-Pd complex (50 Scheme 33)." ... 

The reactions of copper(I) phenylacetylide 325a and copper(I) isopro-penylacetylide 325b with l-hydroxy-2-iodo-3-methoxy-10-methylacridin-9(10//)-one 324 gave furo[2,3-a]acridones 236a and 236b (Scheme 65) (84LA31). 

Reactions. - The reactions of diorganoiodophosphines with varying quantities of iodine have been studied by NMR techniques, which indicate the formation of a dialkyldi-iodophosphonium iodide as the initial product, followed by polyhalide anion formation in the presence of excess iodine. A modified McCormack synthesis of 3-silylated phosphol-3-enes (168) from phenyl-dichlorophosphine and 2-silylated 1,3-butadienes has been described. The reaction is carried out in the presence of a small amount of copper stearate in acetic anhydride at 50 °C, these conditions preventing the complete desilylation observed under standard conditions. The consecutive reaction of lithium phenylacetylide with triphenylborane and diphenylchlorophosphine results in the formation of the intramolecularly coordinated phosphino-borane (169). Treatment of the alkoxyvinyldichlorophosphines (170) with Grignard reagents... 

The principal product of the reaction of 2,3,5-tri-O-benzoyl-D-ribofuranosyl bromide with mercury(ii) or copper(i) phenylacetylide has been shown to possess the 3-configuration by H n.m.r. examination of isopropylidenated and acylated derivatives (7, j = 0 Hz) of the debenzoylated product and by chemical degradation of the side-chain to give known 2,5-anhydro-D-allonic acid derivatives. Details have appeared on the synthesis of methyl 3-(2,3,5-tri-0-benzyl-a- and -P-D-ribofuranosyl)propiolates le.g. (74)] by reaction of 2,3,5-tri-O-benzyl-D-ribo-... 

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