Development of Zn-ProPhenol-Catalyzed Asymmetric Alkyne Addition: Synthesis of Chiral Propargylic Alcohols
作者:Barry M. Trost、Mark J. Bartlett、Andrew H. Weiss、Axel Jacobi von Wangelin、Vincent S. Chan
DOI:10.1002/chem.201202085
日期:2012.12.14
The development of a general and practical zinc‐catalyzed enantioselective alkyneaddition methodology is reported. The commercially available ProPhenol ligand (1) has facilitated the addition of a wide range of zinc alkynylides to aryl, aliphatic, and α,β‐unsaturated aldehydes in high yield and enantioselectivity. New insights into the mechanism of this reaction have resulted in a significant reduction
Asymmetric Catalytic Alkynylation of Acetaldehyde: Application to the Synthesis of (+)-Tetrahydropyrenophorol
作者:Barry M. Trost、Adrien Quintard
DOI:10.1002/anie.201203035
日期:2012.7.2
In control: By controlling the kinetics of alkynylation over aldolization, the challenging asymmetriccatalyticalkynylation of acetaldehyde has been realized. The resulting products are attractive synthons which are produced with good to excellent enantiocontrol, and show broad tolerance and applicability, as demonstrated by the synthesis (+)‐tetrahydropyrenophorol.
Thionium Ion Initiated Medium-Sized Ring Formation: The Total Synthesis of Asteriscunolide D
作者:Barry M. Trost、Aaron C. Burns、Mark J. Bartlett、Thomas Tautz、Andrew H. Weiss
DOI:10.1021/ja210986f
日期:2012.1.25
product asteriscunolide D has been accomplished in nine steps without the use of protecting groups. The challenging 11-membered ring was forged via a diastereoselective thionium ion initiated cyclization, which constitutes a formal aldol disconnection to form a strained macrocycle. A stereospecific thioether activation-elimination protocol was developed for selective E-olefin formation, thus providing access
Three chiral beta-hydroxy amide ligands were prepared by the reaction of benzyl chloride with amino alcohols derived from L-tyrosine. The titanium(IV) complex of chiral ligand 4a was found to be an effective catalyst for the asymmetric addition of methyl propiolate, to aliphatic and aromatic aldehydes. The gamma-hydroxy-alpha,beta-acetylenic esters were obtained in excellent enantiomeric excesses (up to 94% ee) under optimized conditions. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.
A General Asymmetric Synthesis of (R)-Matsutakeol and Flavored Analogs
作者:Jia Liu、Honglian Li、Chao Zheng、Shichao Lu、Xianru Guo、Xinming Yin、Risong Na、Bin Yu、Min Wang
DOI:10.3390/molecules22030364
日期:——
and practical syntheticroute toward chiral matsutakeol and analogs was developed by asymmetric addition of terminal alkyne to aldehydes. (R)-matsutakeol and other flavored substances were feasibly synthesized from various alkylaldehydes in high yield (up to 49.5%, in three steps) and excellent enantiomeric excess (up to >99%). The protocols may serve as an alternative asymmetric synthetic method for