Biocatalytically assisted preparation of antifungal chlorophenylpropanols
摘要:
Fermenting baker's yeast converts 4'-chloropropiophenone 1 and 3'-chloropropiophenone 2 into enantiopure (S)-(-)-1(4'-chlorophenyl)propan-1-ol (S)-3 and (S)-(+)-1-(3'-chlorophenyl)propan-1-ol (S)-4, respectively. Application of inhibitors and organic solvents as additives enhanced the enantiomeric excesses. Enantiopure compounds (R)-(+)-1-(4'-chlorophenyl)propan-1-of ((R)-3) and (R)-(+)-1-(3'-chlorophenyl)propan-1-ol (R)-4 were prepared by lipase-mediated esterifications of the racemic alcohols. Maximum inhibition of the growth of the phytopathougenic fungus Botrytis cinerea was shown for the (R)-enantiomers. (C) 2002 Elsevier Science Ltd. All rights reserved.
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。
Use of diamines containing the α-phenylethyl group as chiral ligands in the asymmetric hydrosilylation of prochiral ketones
作者:Virginia M. Mastranzo、Leticia Quintero、Cecilia Anaya de Parrodi、Eusebio Juaristi、Patrick J. Walsh
DOI:10.1016/j.tet.2003.12.039
日期:2004.2
Chiral diamines 1–7 were used in the enantioselective hydrosilylation of prochiral aromatic and aliphatic ketones. Some of these ligands combine chiral backbones and chiral N,N′-α-phenylethyl substituents that give rise to synergistic effects between these two groups and lead to catalysts that exhibit high enantioselectivity.
Towards practical earth abundant reduction catalysis: design of improved catalysts for manganese catalysed hydrogenation
作者:Magnus B. Widegren、Matthew L. Clarke
DOI:10.1039/c9cy01601e
日期:——
Manganese catalysts derived from tridentate P,N,N ligands can be activated easily using weak bases for both ketone and ester hydrogenations. Kinetic studies indicate the ketone hydrogenations are 0th order in acetophenone, positive order in hydrogen and 1st order in the catalyst. This implies that the rate determining step of the reaction was the activation of hydrogen. New ligand systems with varying
New polymer anchored chiral amino oxazolines as effective catalysts for enantioselective addition of diethylzinc to aldehydes
作者:Nadim S Shaikh、Vishnu H Deshpande、Ashutosh V Bedekar
DOI:10.1016/s0040-4039(02)01139-5
日期:2002.8
The application of a new type of polymer anchored chiral amino-oxazolinyl ligand as catalyst for the enantioselectiveaddition of diethylzinc to aldehydes is reported. The catalyst is effective at a low ligand concentration and can be reused with minimal loss of activity.
Synthesis of a scalemic β-amino disulfide from (S)-phenylglycine and (R)-styrene oxide and use as a catalyst in enantioselective additions of diethylzinc to aldehydes
作者:David A. Fulton、Colin L. Gibson
DOI:10.1016/s0040-4039(97)00221-9
日期:1997.3
Two routes to the novel scalemic β-amino disulfide 7 have been developed from (S)-phenylglycine and (R)-styrene oxide. The β-amino disulfide 7 was used as a catalyst in the enantioselectiveaddition of diethylzinc to aldehydes providing (R)-secondary alcohols in 39–80% ee.