[A novel deprotonative functionalization of aromatics with phosphazene base].
A novel type of deprotonative functionalization of aromatics was accomplished with a phosphazene base (t-Bu-P4 base). For various nitrogen heteroaromatics and benzene derivatives, deprotonative 1,2-additions proceeded with the t-Bu-P4 base and ZnI(2) as an additive in the presence of carbonyl compounds. The t-Bu-P4 base has both extremely strong Brønsted basicity and less nucleophilicity due to its huge, widely conjugated structure, and highly chemoselective deprotonations were achieved. In addition the nonmetallic t-Bu-P4 base should not function as a Lewis acid. Therefore the deprotonation with the t-Bu-P4 base is considered to proceed via a different pathway from traditional deprotonative metalation of aromatics with metallic bases. Some reactions with unique regioselectivities were observed.
Imahori
Tatsushi
T
Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai, Japan. imahoritandon@yahoo.co.jp
D052160:Benzothiazoles; D002625:Chemistry, Organic; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D007454:Iodides; D055601:Organic Chemistry Phenomena; D009943:Organophosphorus Compounds / Q000737:chemistry*; D011522:Protons; D011724:Pyridazines; D011743:Pyrimidines; D013830:Thiadiazoles; D013844:Thiazoles; D017967:Zinc Compounds
D052160:Benzothiazoles; D006841:Hydrocarbons, Aromatic; D007454:Iodides; D009943:Organophosphorus Compounds; D011522:Protons; D011724:Pyridazines; D011743:Pyrimidines; D013830:Thiadiazoles; D013844:Thiazoles; D017967:Zinc Compounds; C015700:benzo-1,2,3-thiadiazole; C062482:pyridazine; C029770:zinc iodide; C005465:benzothiazole; C030986:pyrimidine