在环境温度下,使用SO 2 F 2作为亲电子试剂在DMSO中作为氧化剂和溶剂,伯醇和仲醇进行实用,通用且温和的氧化成羰基化合物的收率可达99%。不需要无湿气和无氧条件。化学计量的廉价K 2 CO 3生成易于分离的副产物的油基用作基础。因此,通过简单的过滤作为后处理,以几乎定量的产量进行了5克规模的运行。还应注意使用通常促进竞争的Pummerer重排的极性溶剂(例如DMSO)。该协议与(杂)芳烃,烯烃和炔烃底物上的各种常见的N-,O-和S-官能团兼容(68个例子)。该方案被应用(99%的产率)用于重要的降胆固醇药物瑞舒伐他汀的正式合成。
PROCESS FOR PRODUCING OPTICALLY ACTIVE 4-CHLORO-3-HYDROXYBUTANAL COMPOUND
申请人:Hayashi Yujiro
公开号:US20130217901A1
公开(公告)日:2013-08-22
The invention relates to a method of producing optically active 4-chloro-3-hydroxybutanal compound (2) by reacting chloroacetaldehyde with aldehyde compound (1) in the presence of optically active pyrrolidine compound (5).
wherein each symbol is as defined in the specification.
Prolinate Salt as a Catalyst in the<i>syn</i>-Selective, Asymmetric Mannich Reaction of Alkynyl Imine
作者:Yujiro Hayashi、Tatsuya Yamazaki、Genki Kawauchi、Itaru Sato
DOI:10.1021/acs.orglett.8b00728
日期:2018.4.20
Prolinate salt is an efficient catalyst in the Mannichreaction of alkynyl imine and aldehyde, to afford synthetically useful chiral propargyl amine derivatives with excellent syn-selectivity and nearly perfect control of the absolute configuration. The counterion of the prolinate salt does not affect the enantioselectivity. This is a rare example, in which proline alkali metals, alkaline-earth metals
SELECTIVE HYDROGENATION OF ALDEHYDE WITH RU/BIDENTATE LIGANDS COMPLEXES
申请人:FIRMENICH SA
公开号:US20140243526A1
公开(公告)日:2014-08-28
The present invention relates to processes for the reduction by hydrogenation, using molecular H
2
, of a C
5
-C
20
substrate containing one or two aldehydes functional groups into the corresponding alcohol or diol, characterized in that said process is carried out in the presence of —at least one catalyst or pre-catalyst in the form of a ruthenium complex having a coordination sphere of the N
2
P
2
O
2
, wherein the coordinating atoms N
2
are provided by a first bidentate ligand, the coordinating atoms P
2
are provided by a second bidentate ligand and the coordinating atoms O
2
are provided by two non-linear carboxylate ligands; and —optionally of an acidic additive.
Unexpected Role of Anionic Ligands in the Ruthenium-Catalyzed Base-Free Selective Hydrogenation of Aldehydes
作者:Philippe Dupau、Lucia Bonomo、Laurent Kermorvan
DOI:10.1002/anie.201304912
日期:2013.10.18
Bigger and better: The replacement of anionic chloride ligands in Noyori‐type [(diamine)(diphosphine)RuCl2] catalysts with bulky carboxylate ligands enabled the efficient selectivehydrogenation of a variety of aldehydes under base‐free conditions (see scheme). Turnover numbers of up to 100 000 were reached in the presence of a bulky carboxylic acid co‐catalyst. This type of catalytic system probably
Mn(III)-based oxidative free-radical cyclizations of alkenyl Meldrum's acids
作者:Barry B. Snider、Rachel B. Smith
DOI:10.1016/s0040-4020(01)01054-7
日期:2002.1
Oxidativecyclization of unsaturated Meldrum's acids can be carried out at temperatures as low as −30°C. The rate-determining step is cyclization of the enolate to the alkene (11 to 14 and 15) rather than enolization, which is the rate-determining step with dimethyl 4-pentenylmalonate (1). While cyclization of 1 gives mainly cyclopentanes, cyclization of Meldrum's acids provides a versatile route to