Zinc reagents amides

Phenylcyclopropane has been prepared by the base catalyzed decomposition of 5-phenylpyrazoline (33 %),2 by the reaction of 1,3-dibromo-l phenylpropane with magnesium (68%),3 and by the reaction of 3-phenylpropyltrimethylammomum iodide with sodium amide in liquid ammonia (80%)4 However, the method frequently used at present is the reaction of styrene with the methylene iodide-zinc reagent (32%)5... 

The chiral a-pyrrolidino imine that is formed in situ in the reaction of a-sulfonyl amide 141 with allylic zinc reagents undergoes addition with mod-... 

On the other hand, the 0-triisopropylsilyl group of 100b cannot direct the cyclopropana-tion reaction and causes non-bonding interaction to restrict rotation about the Cl to C2 bond and covers the front face of the amide moiety. Thus, the (iodomethyl)zinc reagent approaches from the backside of the amide group, resulting in higher diastereoselectivity. ... 

Amines might be protected as the amides (7). What reagent would you need to,put in this protecting group, and how would you make it The product amine (8) might be released by treatment with zinc, suggest a mechanism for this reaction. 

Zinc borohydride, which is also a useful reagent,66 is prepared by reaction of ZnCl2 with NaBH4 in THF. Owing to the stronger Lewis acid character of Zn2+, Zn(BH4)2 is more reactive than NaBH4 toward esters and amides and reduces them to alcohols and amines, respectively.67 Zn(BH4)2 reduces carboxylic acids to primary alcohols.68 The reagent also smoothly reduces a-aminoacids to (3-aminoalcohols.69... 

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