Chiral 2-(2-hydroxyaryl)alcohols (HAROLs) with a 1,4-diol scaffold as a new family of ligands and organocatalysts
作者:Ömer Dilek、Mustafa A. Tezeren、Tahir Tilki、Erkan Ertürk
DOI:10.1016/j.tet.2017.11.054
日期:2018.1
Efficient and modular syntheses of chiral 2-(2-hydroxyaryl)alcohols (HAROLs), novel 1,4-diols carrying one phenolic and one alcohol hydroxyl group, have been developed which led to generation of a small library of structurally diverse HAROLs in enantiomerically pure form. Of the different HAROLs examined, a HAROL based on the indan backbone exhibited the highest activity and enantioselectivity in the
高效和模块化的手性2-(2-羟基芳基)醇(HAROLs)的合成,带有一个酚和一个醇羟基的新型1,4-二醇已被开发出来,这导致在对映异构体中生成结构多样的HAROLS小文库纯形式。在考察的不同HAROL中,基于茚满骨架的HAROL在Ti(O i Pr)4(y高达97%, 88%ee)并在三田膦的促进下在Morita-Baylis-Hillman反应中作为氢键供体有机催化剂发挥作用。
Switching of Enantioselectivity in the Catalytic Addition of Diethylzinc to Aldehydes by Regioisomeric Chiral 1,3-Amino Sulfonamide Ligands
作者:Takuji Hirose、Kazuyuki Sugawara、Koichi Kodama
DOI:10.1021/jo200834n
日期:2011.7.1
Twenty chiral 1,3-amino sulfonamides of two classes (2a–i and 3a–k) have been prepared from (−)-cis-2-benzamidocyclohexanecarboxylic acid (1) and studied as ligands for catalytic enantioselectiveaddition of Et2Zn to a variety of aromatic and aliphatic aldehydes. The ligands 2 and 3 are regioisomers in which the position of the amine and sulfonamide groups is exchanged. Each class of ligands with the
d-Penicillamine derived thiazolidine ligands were prepared in a two-step synthetic sequence and used in the enantioselective alkylation of a variety of aromatic aldehydes with diethylzinc at room temperature. Excellent ee, up to >99%, and nearly complete conversions were observed. Structurally analogous l-cysteine derived thiazolidine ligands were also synthesized and tested for comparative purposes
Synthesis of Chiral Pyridylphenols for the Enantioselective Addition of Diethylzinc to Aldehydes
作者:Pei-Shan Wu、Chinpiao Chen
DOI:10.1002/jccs.201100474
日期:2012.6
Chiral 8‐substituted 2‐(8,10,10‐trimethyl‐6‐aza‐tricyclo[7.1.1.02,7]undeca‐2(7),3,5‐trien‐5‐yl)‐phenols were prepared from a high enantiopurity (>97% ee) of (1R)‐(+)‐α‐pinene, and assessed in the enantioselectiveaddition of diethylzinc to substituted benzaldehydes, giving the (S)‐alcohols with enantiomeric excess ranging from 33% to 89%. Interestingly, in all cases, except for those of ortho‐chlorobenzaldehyde
Enantioselective addition of organozinc reagents to carbonyl compounds catalyzed by a camphor derived chiral γ-amino thiol ligand
作者:Hsyueh-Liang Wu、Ping-Yu Wu、Ying-Ni Cheng、Biing-Jiun Uang
DOI:10.1016/j.tet.2015.07.038
日期:2016.5
synthesis of the chiral camphor derived γ-amino thiol ligand 17 and its application in catalytic enantioselective carbon-carbon forming reactions through the addition of organozinc reagents to carbonyl compounds is described. The catalytic activity and enantioselectivity of ligand 17 is demonstrated in the enantioselective addition of various organozinc reagents to aldehydes and ketoesters, offering the corresponding