The biaryl core structure of rhazinilam with its fixed dihedral angle is a pivotal element for its unique in vitro cytotoxic activity. Most of the related natural products are oxidized versions of rhazinilam. Replacing the sensitive pyrrole ring by a pyrrolinone ring is the basis of our initial strategy towards rhazinilamanalogues. With this goal, variants of the sequence crossed Mukaiyama aldol reaction
α-Thiocyanation of Carbonyl and β-Dicarbonyl Compounds Using (Dichloroiodo)benzene−Lead(II) Thiocyanate
作者:Om Prakash、Harpreet Kaur、Hitesh Batra、Neena Rani、Shiv P. Singh、Robert M. Moriarty
DOI:10.1021/jo001504i
日期:2001.3.1
combination reagent (dichloroiodo)benzene and lead(II) thiocyanate in dichloromethane effects oxidation of various enolsilylethers, ketene silyl acetals, and beta-dicarbonyl compounds, thereby providing an efficient and convenient method for alpha-thiocyanation of carbonyl and beta-dicarbonyl compounds.
Synthesis of α-Fluorocarboxylates from the Corresponding Acids Using Acetyl Hypofluorite
作者:Shlomo Rozen、Aviv Hagooly、Rinat Harduf
DOI:10.1021/jo010677k
日期:2001.11.1
alpha-Fluorocarboxylic esters and acids were synthesized in good yields. The corresponding esters and acids were converted to their ketene acetals, and these enol derivatives reacted with AcOF made directly from fluorine. This route circumvents the problems associated with nucleophilic fluorinations such as various eliminations and rearrangements. alpha- and beta-branched carboxylic acid derivatives that cannot
Mannich-Type Reaction with Trifluoromethylated <i>N</i>,<i>O</i>-Hemiacetal: Facile Preparation of β-Amino-β-trifluoromethyl Carbonyl Compounds
作者:Jun Takaya、Hirotaka Kagoshima、Takahiko Akiyama
DOI:10.1021/ol005812e
日期:2000.6.1
On treatment of silyl enolates and an N,O-hemiacetal, derived from trifluoroacetaldehyde ethyl hemiacetal and p-anisidine, with GaCl(3) (0.2 equiv) and C(6)H(5)COCl (0.2 equiv) in propionitrile, Mannich-type reaction took place smoothly to afford beta-amino-beta-trifluoromethyl carbonylcompounds in high yields.
Reaction of -silyl imines with silyi keteneacetals in the presence of ZnI2 and t-butyl alcohol, followed by treatment of the intermediate -silyl β-aminoesters with MeMgBr, produces -silyl-azetidin-2-ones in good yield; use of trimethylsilyl triflate as Lewis acid catalyst can be advantageous in some cases. The preparation of the -t-butyldimethylsilyl imine of ethyl glyoxylate in this context is detailed