Improved Conditions for the Proline-Catalyzed Aldol Reaction of Acetone with Aliphatic Aldehydes
作者:Benjamin List、Alberto Martínez、Kristina Zumbansen、Arno Döhring、Manuel van Gemmeren
DOI:10.1055/s-0033-1340919
日期:——
The proline-catalyzed asymmetric aldol reaction between aliphatic aldehydes and acetone has, to date, remained underdeveloped. Challenges in controlling this reaction include avoiding undesired side reactions such as aldol condensation and self-aldolization. In recent years we have developed optimized conditions, which enable high yields and good to excellent enantioselectivities, and which are presented
Chiral organoaluminum complex 1 efficiently catalyzed the asymmetric hetero-ene reaction of commercially available 2-methoxypropene (2) with aldehydes under mild conditions to give the corresponding β-hydroxymethyl ketones 3 in good to excellent chemical yields with high enantiomeric excesses. The asymmetriccatalysis of 1 was further applied to the carbonyl addition of methallylsilanes, where exclusive
Preparation of Chiral β-Hydroxyketones by Aldol-type Condensation of Chiral<i>p</i>-Tolylsulfinylmethyl Ketones
作者:Fernand Schneider、Roland Simon
DOI:10.1055/s-1986-31715
日期:——
Chiral ß-hydroxyketones 7 with fair e.e. were prepared by treating newly prepared optically pure p-tolylsulfinylmethyl ketones 4 with t-butyl-magnesium bromide and aldehydes 5 followed by desulfurization with aluminium amalgam.
Silica Jar‐with‐Lid as Chemo‐Enzymatic Nano‐Compartment for Enantioselective Synthesis inside Living Cells
作者:Seonock Kim、Nitee Kumari、Jongwon Lim、Sateesh Dubbu、Amit Kumar、In Su Lee
DOI:10.1002/anie.202103165
日期:——
synthetic catalysts and enzymes to perform enantioselectivesynthesisinsidecell, have never been reported. Here, we synthesized round bottom jar-like silica nanostructures (SiJARs) with a chemo-responsive metal-silicate lid. This was isolated as an intermediate structure during highly controlled solid-state nanocrystal-conversion at the arc-section of silica shell. Different catalytic noble metals (Pt
从未报道过利用合成催化剂和酶的力量在细胞内进行对映选择性合成的纳米装置。在这里,我们合成了带有化学响应金属硅酸盐盖的圆底罐状二氧化硅纳米结构 ( SiJAR ) 。这是在二氧化硅壳的弧形截面处高度受控的固态纳米晶体转化过程中作为中间结构被分离出来的。不同的催化贵金属(Pt、Pd、Ru)通过电流反应在盖子部分被选择性地改性。还有,盖子孔径受温和的酸性条件或容纳金属纳米晶体和酶的细胞内环境调节,进而产生开口纳米反应器。与游离酶不同,SiJAR s 进行不对称醛醇反应,具有高活性和对映选择性(产率 >99%,ee =95%),并且还充当活细胞内的人工催化细胞器。这项工作将复杂的纳米晶体转化化学和用于新自然催化的先进平台的巨大潜力联系起来。
Catalytic compositions and methods for asymmetric aldol reactions
申请人:——
公开号:US20020147367A1
公开(公告)日:2002-10-10
Methods and compositions are provided for the direct catalytic asymmetric aldol reaction of aldehydes with donor molecules selected from ketones and nitroalkyl compounds. The reactions employ as catalyst a Group 2A or Group 2B metal complex of a ligand of formula I, as defined further herein.
1