decarboxylase (PDC) from Saccharomyces cerevisiae provide different CC bond forming possibilities of α,β-unsaturated aldehydes with aliphatic and aromatic aldehydes. Structure elucidation and determination of the absolute configuration of the products, which were obtained with high regio- and stereoselectivity were carried out. Selective 1,2-reactivity with yields of 75% and >98% ee, for one single isomer
A Gold(I)-Catalyzed Intramolecular Reaction of Propargylic/Homopropargylic Alcohols with Oxirane
作者:Lun-Zhi Dai、Min Shi
DOI:10.1002/chem.200701954
日期:2008.7.1
The gold(I)-catalyzedcycloisomerization of epoxy alkynes in the presence of a nucleophile is an efficientprotocol to provide ketal skeletons with high stereoselectivity. An intramolecular reaction of propargylic/homopropargylic alcohols with oxirane to produce ketal/spiroketals in moderate yields under mild conditions has been reported. Moreover, the mechanism of this kind of reaction has been discussed
作者:Robert K. Bressin、Sami Osman、Ivanna Pohorilets、Upamanyu Basu、Kazunori Koide
DOI:10.1021/acs.joc.9b03370
日期:2020.4.3
this synthesis highlights a scalable Mukaiyama aldol reaction, Nicolaou-type epoxide opening reaction, stereoselective Corey–Chaykovsky-type reaction, and a modified Horner–Wadsworth–Emmons Z-selective olefination. We also discuss a Z–E isomerization during the α,β-unsaturated amide formation. The new synthesis of meayamycin B consists of 11 steps in the longest linear sequence and 24 total steps
Chiral rhodium(II)-catalyzed asymmetric aldol-type interception of an oxonium ylide to assemble chiral 2,3-dihydropyrans
作者:Aimin Xu、Xiaoyu Zhou、Rimei Zheng、Zhijing Zhang、Xinru Yin、Kemiao Hong、Zhuofeng Ke、Yu Qian、Wenhao Hu
DOI:10.1007/s11426-022-1275-9
日期:2022.8
A chiral dirhodium complex is an effective and robust catalyst for asymmetric carbene transformations. However, dirhodium-catalyzed asymmetric ylide interception processes are rare, mainly because of the dissociation of the metal catalyst before the stereo-determining step. Herein, we report a chiral dirhodium(II)-catalyzed asymmetricannulation of vinyl diazoesters with α-hydroxyl ketones, which provides
Gold(I)-Catalyzed Rearrangement of Propargylic Alcohols to α,β-Unsaturated Ketones
作者:Young Chung、Sang Lee、Ji Baek、So Sim
DOI:10.1055/s-2007-983725
日期:——
We have developed a gold(I)-catalyzed rearrangement of propargylic alcohols to α,β-unsaturated ketones. The reaction might proceed through a dehydration of an alkynol, followed by an addition of water to a cumulene intermediate. The substituents of the alkynol play an important role in the rearrangement.