Alkylation of Aldehyde (Arenesulfonyl)hydrazones with Trialkylboranes
作者:George W. Kabalka、John T. Maddox、Ekaterini Bogas、Shane W. Kelley
DOI:10.1021/jo962089q
日期:1997.5.1
(Arenesulfonyl)hydrazone derivatives of aryl aldehydes are readily alkylated by trialkylboranes in the presence of base to generate new organoboranes that may be converted to the corresponding substituted alkanes or alcohols depending upon the reaction conditions chosen. Both tosyl- and trisylhydrazone derivatives can be utilized in the reaction, which tolerates a variety of functional groups, making it a versatile alternative to both the Grignard and Suzuki-coupling reactions.
Selectivity in Organic Group Transfer in Reactions of Mixed Diorganomanganese(II) and Triorganomanganate(II) with 2-Cyclohexen-1-one or Cyclohexanecarbaldehyde
The unsymmetrical diorganomanganeses(II) (R1R2Mn) and magnesium triorganomanganates(II) (R12R2MnMgX) reacted with 2-cyclohexen-1-one to produce the 1,4-addition products in moderate to good yields. The approximate reactivity order obtained from the product distribution was CH2=CHCH2 > PhS > n-Bu > Ph > Me, Me3SiCH2, n-C6H13–C≡C. In contrast, the reactivity order for the addition of these reagents to
PROCESS FOR PREPARATING OPTICALLY ACTIVE COMPOUNDS
申请人:Japan Science and Technology Corporation
公开号:EP0916637A1
公开(公告)日:1999-05-19
The present invention relates to a novel, highly practical method for producing optically active compounds such as optically active alcohol and optically active amine useful for various utilities such as synthetic intermediates of drugs, liquid crystal materials, and optical resolution agents, comprising hydrogen transfer-type asymmetric reduction in the presence of a transition metal catalyst and an optically active nitrogen-containing compound or a transition metal catalyst with an optically active nitrogen-containing compound as the asymmetric ligand, and a hydrogen-donating organic or inorganic compound.
In accordance with the present invention, characteristically, an optically active secondary alcohol can be recovered through the hydrogen transfer-type oxidation from racemic secondary alcohol or meso-type diol.
Synthesis of .alpha.-hydroxy ketones by direct, low-temperature, in situ nucleophilic acylation of aldehydes and ketones by acyllithium reagents
作者:Dietmar Seyferth、Robert M. Weinstein、Richard C. Hui、Wei Liang Wang、Colin M. Archer
DOI:10.1021/jo00047a014
日期:1992.10
The reaction of n-, sec-, and tert-butyllithium with CO at atmospheric pressure at -110 and -135-degrees-C in the appropriate solvent system in the presence of ketones and aldehydes generates the acyllithium, RC(O)Li, which reacts with the carbonyl compound to give the alpha-hydroxy ketone, generally in good yield. Reactions with aldehydes are limited in scope, working well with the t-BuLi-derived acyllithium reagents, but not with n-BuC(O)Li.