Enantioselective synthesis of (S)- and (R)-fluoxetine hydrochloride
摘要:
The enantioselective synthesis of fluoxetine hydrochloride, a potent serotonin-uptake inhibitor, is described. The synthesis of (S)-fluoxetine hydrochloride begins with the asymmetric carbonyl-ene reaction of benzaldehyde with 3-methylene-2,3-dihydrofuran (1) catalyzed by Ti[OCH(CH3)(2)](4)/(S)-BINOL to give (S)-2-(3-furyl)-1-phenyl-1-ethanol (2) in 90% yield and 95% ee. In five steps, alcohol 2 was converted into (S)-fluoxetine hydrochloride (97% ee and 56% overall yield from benzaldehyde). (R)-fluoxetine hydrochloride was prepared by the same sequence except that Ti[OCH(CH3)(2)](4)/(R)-BINOL was used in the first reaction to give the enantiomer of 2. (C) 2001 Elsevier Science Ltd. All rights reserved.
Coordinated carbenes from electron-rich olefins on RuHCl(PPr3i)2
作者:Joseph N. Coalter III、John C. Bollinger、John C. Huffman、Ulrike Werner–Zwanziger、Kenneth G. Caulton、Ernest R. Davidson、He´lène Ge´rard、Eric Clot、Odile Eisenstein
DOI:10.1039/a907624g
日期:——
model. Less electron-rich vinyl amides or amines form η2-olefin complexes, but do not isomerize to carbenecomplexes. Calculated ΔE values for selected ‘‘ competition’’ reactions reveal that donation by both Ru and the heteroatom-substituted X are necessary to make the carbenecomplex L2HClRuC(X)(CH3) more stable than the olefincomplex L2HClRu(η2-H2CCHX). This originates in part from a diminished
RuH 2 Cl 2 L 2 (L = PPr 3 i)的脱卤化氢得到(RuHClL 2)2,通过X射线晶体学显示为卤化物桥连的二聚体。氟化物类似物也是二聚体。(RuHClL 2)2与N 2,吡啶和C 2 H 4(L')反应生成RuHClL'L 2,但与乙烯基醚和乙烯基酰胺H 2 C CH(E)[E = OR,NRC(O )R'],这样的烯烃键合后异构化为杂原子取代的卡宾配合物L 2 HClRu C(CH 3)(E)。通过DFT(B3PW91)计算,对于作为烯烃的C 2 H 4(发现有吸热性),通过DFT(B3PW91)计算确定了这种重排的反应机理,并针对H 2 C C(H)(OCH 3)计算了中间体的结构)和环状和非环状酰胺取代的烯烃。从实验和计算上都发现,酰胺氧结合到Ru上,对于非环状模型,计算出的结合能约为9 kcal mol -1。少富电子乙烯基酰胺或胺形成η 2个烯烃配合物,但不
Catalytic, Enantioselective Alkylation of α-Imino Esters: The Synthesis of Nonnatural α-Amino Acid Derivatives
作者:Dana Ferraris、Brandon Young、Christopher Cox、Travis Dudding、William J. Drury、Lev Ryzhkov、Andrew E. Taggi、Thomas Lectka
DOI:10.1021/ja016838j
日期:2002.1.1
Methodology for the practical synthesis of nonnatural amino acids has been developed through the catalytic, asymmetric alkylation of α-imino esters and N,O-acetals by enol silanes, ketene acetals, alkenes, and allylsilanes using chiral transition metal-phosphine complexes as catalysts (1−5 mol %). The alkylation products, which are prepared with high enantioselectivity (up to 99% ee) and diastereoselectivity
Synthesis and ene reactions of 3-methylene-2,3-dihydrofuran
作者:William H. Miles、Christina L. Berreth、Patricia M. Smiley
DOI:10.1016/s0040-4039(00)73957-8
日期:1993.8
The unexpected formation of 3-methylene-2,3-dihydrofuran 1 using the Huang-Minlon modification of the Wolff-Kishner reduction of 3-furaldehyde is discribed. Furan 1 readily undergoes enereactions with simple electron-deficient alkenes.
Furan approach to the synthesis of the A-ring of Vitamin D analogues
作者:William H. Miles、Katelyn B. Connell
DOI:10.1016/s0040-4039(02)02824-1
日期:2003.2
The efficient transformation of 2,3-disubstituted furan (3) into (Z)-dienol (2) illustrates a useful strategy for the synthesis of the A-ring of Vitamin D analogues.