Reductive Dehalogenation ofα-Haloketones Promoted by Hydroiodic Acid and Without Solvent
摘要:
Several alpha-haloketones have been transformed into the corresponding ketones by reaction with aqueous 57% HI, without solvent. The products are obtained in nearly quantitative yields and with high purity (>99%) even in the case of sterically hindered starting materials.
Catalytic dehydrogenative dual functionalization of ethers: dealkylation–oxidation–bromination accompanied by C–O bond cleavage via aerobic oxidation of bromide
A catalytic dehydrogenative dual functionalization (DDF) of ethers viaoxidation, dealkylation, and α-bromination by the aerobic oxidation of bromide was developed to obtain the corresponding α-bromo ketones in high yields. In particular, the reaction of substituted tetrahydrofurans as cyclic ethers provided 3,3-dibromo tetrahydrofuran-2-ols in high yields selectively through the double α-bromination
Free-radical addition reaction of organoboranes to α, β-unsaturatedketones forms corresponding vinyloxyboranes (3) as the intermediate. Methanolysis of the dibromoderivatives which should be obtained by bromination of the initially formed vinyloxyboranes provides a convenient one-step synthetic procedure of α-bromoketones from organoboranes in good yields.
4,3 additions to α,β-unsaturated ketones via η2 CC binding to a ruthenium complex.
作者:Robin S. Tanke、Robert H. Crabtree
DOI:10.1016/s0040-4039(00)82442-9
日期:——
The [Cp*Ru(CO)P2]+ fragment (Cp* = η5-C5Me5) binds α,β-unsaturatedketones in an η2-CC fashion. The resulting complex is subject to attack by H− at the 4-position, leaving the ruthenium bound to the substrate at the 3-position. The RuC bond, formed in this way, can be cleaved to give a variety of 4,3-addition products.
Solvent-free oxidation of aliphatic alcohols with ceric ammonium nitrate—lithium bromide system
作者:N. I. Kapustina、L. L. Sokova、R. G. Gasanov、G. I. Nikishin
DOI:10.1007/s11172-007-0232-8
日期:2007.8
Esters are formed during the solvent-free oxidation of primary aliphatic C5–C9 alcohols with Ce(NH4)2(NO3)6–LiBr, whereas secondary octan-2-ol gives a mixture of isomeric 1-and 3-bromooctan-2-ones.