Alcohol versus alcohol: A highly stereocontrolled synthesis of substituted morpholines is realized by means of gold‐catalyzed dehydrative allylic cyclization of diols (see scheme for one example; segphos = 5,5′‐bis[di(3,5‐di‐tert‐butyl‐4‐methyoxyphenyl)phosphine]‐4,4′‐bi‐1,3‐benzodioxole). The present methodology represents one of the few examples of enantioselective gold‐catalyzed transformations
Yttrium-Catalyzed Intramolecular Hydroalkoxylation/Claisen Rearrangement Sequence: Efficient Synthesis of Medium-Sized Lactams
作者:Bo Zhou、Long Li、Xin-Qi Zhu、Juan-Zhu Yan、Yi-Lin Guo、Long-Wu Ye
DOI:10.1002/anie.201700596
日期:2017.3.27
An efficient yttrium‐catalyzed intramolecular hydroalkoxylation/Claisen rearrangement sequence has been achieved, thus enabling facile access to a diverse array of valuable medium‐sized lactams. Furthermore, a mechanistic rationale for this novel cascade reaction is well supported by a variety of control experiments.
We have developed a highly regio- and stereoselective synthesis of medium-sized heterocycles containing one or two heteroatoms via cyclization of bromoallenes bearing an oxygen, nitrogen, or carbon nucleophilic functionality in the presence of a palladium(0) catalyst and alcohol. In this reaction, bromoallenes act as an allyl dication equivalent, and the intramolecular nucleophilic attack takes place
Asymmetric Hydrative Aldol Reaction (HAR) via Vinyl‐Gold Promoted Intermolecular Ynamide Addition to Aldehydes
作者:Teng Yuan、Kelton Radefeld、Chuan Shan、Carter Wegner、Erin Nichols、Xiaohan Ye、Qi Tang、Lukasz Wojtas、Xiaodong Shi
DOI:10.1002/anie.202305810
日期:2023.8
application of Fe(acac)3 as a cocatalyst prevents vinyl gold protodeauration, allowing for its nucleophilic addition to aldehydes. Hence, the intermolecular vinyl gold-promoted asymmetric hydrative aldolreaction (HAR) of ynamides and aldehydes was shown possible and is herein presented. The reaction leads to β-hydroxy amides with high yields (up to 95 %) and stereoselectivity (up to >20 : 1 d.r, 99 % ee) under