Tert-Butylmagnesium bromide, reaction

The rate of the reaction decreases with increasing number of substituents in the acetylenic halide, and it is higher with acetylenic bromides than with the corresponding chlorides. Methyl magnesium iodide gives equal amounts of 1,1- and 1,3--substitution products, whereas tert.-butylmagnesium bromide does not react. However, for some tert.-butyl substituted allenes there exists an attractive com-... 

To a stirred solution of 29 mg (0.2 mmol) of copper(I) bromide in 10 mL of diethyl ether under nitrogen are added 504 mg (4 mmol) of 3-[( R,R)- l,2-dimethyTl,2-ethanediylbis(oxy)]-l-propyne in 20 mL of diethyl ether. After cooling to — 50 °C lOmL (8 mmol) of a 0.8 M solution tert-butylmagnesium bromide in diethyl ether are added and the reaction is followed by TLC using cyclohexane. diethyl ether 90 10 as eluant. After completion, hydrolysis is achieved by the addition of 50 mL of aq NH3/NH4C1 and the product is extracted with diethyl ether. The solvent is evaporated and the pure product is stored over K2C03 yield 663 mg (90%) d.r. >98 <2. 

Intermediates 162 may be generated electrochemically,224,225 with zinc,219,221,223 sodium, potassium, magnesium,221 or organometallics.2,8,220 An electron-transfer mechanism for a reaction of perchlorate 158 with tert-butylmagnesium bromide was considered220 as follows (Eq. 7). 

Attempted Grignard reaction of cyclohexanone with tert-butylmagnesium bromide gives only about 1% yield of the expected addition product along with 99% unreacted cyclohexanone. If D30 is added to the reaction mixture after a suitable period, however, the "unreacted" cyclohexanone is found to have one deuterium atom incorporated into it. Explain. 

Butyl hypochlorite, warning, 44, 26 N-chlorination of amines with, 41, 82 M-Butyl isocyanide, 41,14 tert-Butyl isocyanide, 41,14 n-Butylmagnesium bromide, 41, 61 reaction with rec-butyl crotonate, 41, 61... 

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