Redox-Neutral Rhodium(III)-Catalyzed Chemospecific and Regiospecific [4+1] Annulation between Indoles and Alkenes for the Synthesis of Functionalized Imidazo[1,5-<i>a</i>]indoles
unit, a redox-neutral rhodium(III)-catalyzed chemo- and regiospecific [4+1] annulation between indoles and alkenes for the synthesis of functionalized imidazo[1,5-a]indoles has been achieved. Internal alkenes employed here can fulfill an unusual [4+1] annulation rather than normal [4+2] annulation/C–Halkenylation. This method is characterized by excellent chemo- and regioselectivity, broad substrate scope
利用嵌入氧化功能/离去基团的内部烯烃作为稀有和非常规的单碳单元,氧化还原中性铑(III)催化的吲哚和烯烃之间的化学和区域特异性[4 + 1]环化,用于合成功能化咪唑并[1,5- a ]吲哚已经实现。这里使用的内部烯烃可以实现不寻常的 [4+1] 环化,而不是正常的 [4+2] 环化/C-H 烯基化。该方法的特点是优异的化学和区域选择性、广泛的底物范围、良好的官能团耐受性、良好的收率和氧化还原中性条件。
Lewis acid-catalyzed annulative partial dimerization of 3-aryloxyacrylates to 4-arylchroman-2-ones: synthesis of analogues of tolterodine, RORγ inhibitors and a GPR40 agonist
作者:Rupesh A. Kunkalkar、Rodney A. Fernandes
DOI:10.1039/c8cc09785b
日期:——
annulative partial dimerization of 3-aryloxyacrylates to 4-arylchroman-2-ones catalyzed by Lewis acid (BF3·OEt2) has been developed. The reaction involves two molecules of 3-aryloxyacrylate, resulting in the loss of one propiolate molecule to furnish 4-arylchroman-2-one, an important structural motif found in many natural products. This methodology has been elaborated to synthesize analogues of tolterodine
Potassium <i>tert</i>-butoxide mediated aerobic hydroxylation of arylboronic acids: an application towards the synthesis of (<i>E</i>)-phenoxy acrylates
作者:Ibrahim Muhammad、Madasamy Hari Balakrishnan、Manickam Sasidharan、Subramaniyan Mannathan
DOI:10.1039/c9nj02121c
日期:——
The first example of potassiumtert-butoxidemediated aerobic hydroxylation of arylboronic acids is described. A variety of arylboronic acids bearing both electron donating and withdrawing substituents successfully participated in the reaction and furnished phenols in good yields. This strategy also provides access to one pot synthesis of (E)-3-phenoxy acrylates from arylboronic acids and propiolates
Palladium-catalyzed aerobic regio- and stereo-selective olefination reactions of phenols and acrylates<i>via</i>direct dehydrogenative C(sp<sup>2</sup>)–O cross-coupling
作者:Yun-Bin Wu、Dan Xie、Zhong-Lin Zang、Cheng-He Zhou、Gui-Xin Cai
DOI:10.1039/c8cc01226a
日期:——
An efficient olefination protocol for the oxidative dehydrogenation of phenols and acrylates has been achieved using a palladium catalyst and O2 as the sole oxidant. This reaction exhibits high regio- and stereo-selectivity (E-isomers) with moderate to excellent isolated yields and a wide substrate scope (32 examples) including ethyl vinyl ketone and endofolliculina.