Catalytic Enantioselective Protonation of α-Oxygenated Ester Enolates Prepared through Phospha-Brook Rearrangement
作者:Masashi Hayashi、Shuichi Nakamura
DOI:10.1002/anie.201007568
日期:2011.3.1
chiral: The organocatalytic enantioselective reaction of α‐ketoesters with phosphites using cinchona alkaloids and Na2CO3 has afforded α‐phosphonyloxy esters with high enantioselectivities (see scheme). This process allows the formation of both enantiomers of the product. A catalyst loading of as low as 2 mol % does not result in a significant decrease of the enantioselectivity.
膦酸酯变为手性:使用金鸡纳生物碱和Na 2 CO 3,α-酮酸酯与亚磷酸酯的有机催化对映选择性反应提供了高对映选择性的α-膦酰氧基酯(参见方案)。该过程允许形成产物的两种对映异构体。低至2mol%的催化剂负载量不会导致对映选择性的显着降低。
METHOD FOR MANUFACTURING TRICYCLODECANE MONO-METHANOL MONOCARBOXYLIC ACID DERIVATIVE
申请人:Kawakami Hiroyuki
公开号:US20120203026A1
公开(公告)日:2012-08-09
Provided is a method for manufacturing a tricyclodecane mono-methanol monocarboxylic acid derivative that can be used as a raw material for high heat-resistant alicyclic polyesters and the like.
The provided method for manufacturing a tricyclodecane mono-methanol monocarboxylic acid derivative is characterized in that a tricyclodecane mono-methanol monocarboxylic acid derivative represented by the following formula (III) is obtained by reacting the dicyclopentadiene represented by the following formula (I) with a formic acid compound in the presence of a catalytic system containing a ruthenium compound, a cobalt compound, and a halide salt, to give a tricyclodecene monocarboxylic acid derivative represented by the formula (II), and then hydroformylating the tricyclodecene monocarboxylic acid derivative.
(in the formulae (II) and (III), R represents a hydrogen, an alkyl group having 1 to 5 carbon atoms, a vinyl group, or a benzyl group.)
Preparation of <i>Z</i>-α,β-Unsaturated Diazoketones from Aldehydes. Application in the Construction of Substituted Dihydropyridin-3-ones
作者:Isac G. Rosset、Antonio C. B. Burtoloso
DOI:10.1021/jo401191s
日期:2013.9.20
The stereoselective preparation of α,β-unsaturateddiazoketones with Z geometry is described from aldehydes and a new olefination reagent. When prepared from amino aldehydes, these diazoketones could be converted to substituted dihydropyridin-3-ones in just one step, after an intramolecular N–H insertion reaction. The straightforward synthesis of a natural trihydroxylated piperidine demonstrates the
Direct Enantioselective Three-Component Kabachnik-Fields Reaction Catalyzed by Chiral Bis(imidazoline)-Zinc(II) Catalysts
作者:Mutsuyo Ohara、Shuichi Nakamura、Norio Shibata
DOI:10.1002/adsc.201100482
日期:2011.12
A direct three-component reaction of aldehydes, amines and diaryl phosphites was catalyzed by a zinc(II) complex of 1,3-bis(imidazolin-2-ly)pyridine (pybim) giving the corresponding α-aminophosphonates in good yield with good enantioselectivity. The reaction was applied to a wide variety of aromatic aldehydes to give products with excellent yields (up to 99%) and enantiomeric excesses (up to 93% ee)
The resin of the invention comprises both a phosphorus-containing residue having a bicycloalkyl structure and a specific divalent phenol residue. The invention provides a resin having excellent optical properties, which is colorless and transparent, has a high refractive index and is optically low dispersive, as well as its molded product.