Traceless Chelation-Controlled Rhodium-Catalyzed Intermolecular Alkene and Alkyne Hydroacylation
作者:Joel F. Hooper、Rowan D. Young、Andrew S. Weller、Michael C. Willis
DOI:10.1002/chem.201204056
日期:2013.2.25
A new functional‐group tolerant, rhodium‐catalyzed, sulfide‐reduction process is combined with rhodium‐catalyzed chelation‐controlled hydroacylation reactions to give a traceless hydroacylation protocol. Aryl‐ and alkenyl aldehydes can be combined with both alkenes, alkynes and allenes to give traceless products in high yields. A preliminary mechanistic proposal is also presented.
A rhodium(III)-based catalytic system has been used to develop a C−H bond activation of benzaldehyde derivatives and subsequent functionalization with dioxazolones in order to afford imides. The importance of the nature of the directing group to perform selectively the aldehydic C−H bond activation has been highlighted. The scope investigation showed that this transformation could be applied to various
Direct Synthesis of Highly Substituted Pyrroles and Dihydropyrroles Using Linear Selective Hydroacylation Reactions
作者:Manjeet K. Majhail、Paul M. Ylioja、Michael C. Willis
DOI:10.1002/chem.201600311
日期:2016.6.1
diphosphine ligands, such as (Cy2 P)2 NMe or bis(diphenylphosphino)methane (dppm), are effective at catalysing the union of aldehydes and propargylic amines to deliver the linear hydroacylation adducts in good yields and with high selectivities. In situ treatment of the hydroacylation adducts with p-TSA triggers a dehydrative cyclisation to provide the corresponding pyrroles. The use of allylic amines, in place
Exploiting rhodium-catalysed ynamide hydroacylation as a platform for divergent heterocycle synthesis
作者:Robert N. Straker、Manjeet K. Majhail、Michael C. Willis
DOI:10.1039/c7sc03795c
日期:——
yield and excellent regioselectivity from the combination of aldehydes and ynamides. The enaminone products are subsequently used as a platform to construct a diverse array of substitutedpyrazoles, pyrimidines, and isoxazoles in a two-step, one-pot sequence. It was found that with judicious choice of catalyst system it was possible to overturn the regioselectivity of the hydroacylation reaction to
Herein we use time‐resolved absorption spectroscopy and Hammettanalysis to discover an unexpected principal limit to the photoisomerization rate for donor‐substituted HTIs. By using stationary absorption and fluorescence measurements in combination with theoretical investigations, we offer a detailed mechanistic explanation for the observed rate limit. An alternative way of approaching and possibly even