Efficient Reduction of 2-Haloacetophenone Derivatives to the Corresponding Halohydrins by 9,10-Dihydro-10-methylacridine in the Presence of Titanium Tetrachloride, Comparison with the Reduction in the Presence of Perchloric Acid
derivatives are reduced by an acid-stable NADH model compound, 9,10-dihydro-10-methylacridine, in the presence of HClO4 in acetonitrile at 335 K to yield 10-methylacridinium ion and the parent acetophenone derivatives as well as halohydrins, while the reduction of 2-haloacetophenone derivatives in the presence of TiCl4 in dichloromethane undergoes much more readily even at 298 K to yield the corresponding
2-卤代苯乙酮衍生物被酸稳定的 NADH 模型化合物 9,10-二氢-10-甲基吖啶还原,在 HClO4 存在下,在 335 K 的乙腈中生成 10-甲基吖啶离子和母体苯乙酮衍生物以及卤代醇,而在二氯甲烷中 TiCl4 存在下 2-卤代苯乙酮衍生物的还原即使在 298 K 下也更容易发生,以选择性地产生相应的卤代醇。
Silica Sulfuric Acid-promoted Deacylation of α-Bromo-β-diketones
Novel deacylation of α-bromo-β-diketones using silica sulfuric acid (SSA) has been developed. Deacylation of 3-bromopentane-2,4-diones and 2-bromobutane-1,3-diones were carried out in the presence of SSA in dichloroethane under mild conditions to obtain the corresponding α-bromo ketones in good to excellent yields. SSA also promoted the Friedel–Crafts type alkylation of benzene with 3-(sec-alkyl)-2,4-pentanediones to give the corresponding triarylmethanes in high yields in benzene.
Flow technology enabled preparation of C3-heterosubstituted 1-azabicyclo[1.1.0]butanes and azetidines: accessing unexplored chemical space in strained heterocyclic chemistry
The use of flow technology as an enabling tool for accessing 1-azabicyclo[1.1.0]butanes bearing strained 3-, 4-, and 5-membered O-heterocycles with C3(N-het)–C2(O-het) connectivity is reported. Reactivity and chemoselectivity (N-ring vs. O-ring) were also evaluated. New chemical space has been explored and new structural motifs such as ABB-aziridines or spiro azetidine-oxazetidines are also reported
Simple and efficient methods were developed for sp(2)-sp(3) and sp(3)-sp(3) C-C bond-activation reactions of 2-substituted 1,3-diketones. 3-Substituted 3-bromopentane-2,4-diones were deacylated in the presence of an aromatic compound and a silica gel supported Bronsted acid containing sulfonic groups. The carbocation formed by cleavage of the sp(3)-sp(3) C-C bond of the dione alkylated the aromatic compound.