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As the name suggests, a non-nucleophilic base is an organic base that is a poor nucleophile. Normal bases are also nucleophiles, but often chemists seek the proton-removing ability of a base without any other functions. Typical non-nucleophilic bases are bulky, such that protons can attach to the basic center but alkylation and complexation is inhibited. ==Non-nucleophilic bases== A variety of amines and nitrogen heterocycles are useful bases of moderate strength (pKa of conjugate acid around 10-13) *N,N-Diisopropylethylamine, or DIPEA (also called Hünig's Base)〔K. L. Sorgi, "Diisopropylethylamine," Encyclopedia of Reagents for Organic Synthesis, 2001. 〕 *1,8-Diazabicycloundec-7-ene, or DBU—a favorite for the E2 elimination reaction *2,6-Di-tert-butylpyridine, a weak non-nucleophilic base〔Rafael R. Kostikov, Sánchez-Sancho Francisco, María Garranzo and M. Carmen Murcia "2,6-Di-t-butylpyridine" Encyclopedia of Reagents for Organic Synthesis 2010. 〕 *Phosphazene bases, such as t-Bu-P4〔''Activation in anionic polymerization: Why phosphazene bases are very exciting promoters'' S. Boileau, N. Illy Prog. Polym. Sci., 2011, 36, 1132-1151, 〕 Non-nucleophilic bases of high strength are usually anions. For these species the pKa's of the conjugate acid is around 35-40. * Lithium diisopropylamide, or LDA * Silicon-based amides, such as sodium and potassium bis(trimethylsilyl)amide (NaHMDS and KHMDS, respectively) * Lithium tetramethylpiperidide, or LiTMP (''harpoon base'') Other strong non-nucleophilic bases are sodium hydride and potassium hydride. These compounds are dense, salt-like materials that are insoluble and operate by surface reactions. Some reagents are of high basicity (pKa of conjugate acid around 17) but of modest but not negligible nucleophilicity. Examples include sodium tert-butoxide and potassium tert-butoxide. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Non-nucleophilic base」の詳細全文を読む スポンサード リンク
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