Asymmetric1,4-addition of arylboronicacids to (E)-methyl 2-cyano-3-arylpropenoates proceeded in the presence of a rhodium catalyst (3 mol %) coordinated with a chiral diene ligand, (R,R)-Ph-bod*, to give high yields of the corresponding methyl 3,3-diaryl-2-cyanopropanoates with high enantioselectivity (up to 99% ee). This catalytic asymmetric transformation was applied to the asymmetric synthesis
在具有手性二烯配体(R,R)-Ph- bod *,以高对映选择性(至多99%ee)得到高产率的相应的3,3-二芳基-2-氰基丙酸甲酯。该催化不对称转化应用于(R)-托特罗定的不对称合成。
Stepwise Palladium-Catalyzed 1,4-Addition of Arylboronic Acids to Enones and Regioselective Baeyer–Villiger Oxidation for Enantioselective Synthesis of β-Diaryl Esters and (+)-(<i>R</i>)-Tolterodine
Baeyer-Villiger oxidation of chiral β-diaryl ketones synthesized by 1,4-addition of arylboronicacids to β-aryl-α,β-unsaturated ketones catalyzed by a palladium(2+)-chiraphos complex provided optically active /3-diaryl esters up to 98% ee. The protocol was applied to the synthesis of a potent competitive muscarinic receptor antagonist, (R)-tolterodine (21), which has a chiral center consisting of two
Expeditious Synthesis of Benzopyrans via Lewis Acid-Catalyzed C−H Functionalization: Remarkable Enhancement of Reactivity by an <i>Ortho</i> Substituent
An expeditious construction of a benzopyran skeleton via Lewis acid-catalyzed C−H functionalization was achieved. In this process, a [1,5] hydride shift and 6-endo cyclization successively occurred to give benzopyrans. The presence of substituents ortho to the alkoxygroup significantly enhanced the reactivity, affording the desired compounds in excellent chemical yields with short reaction times.
Potassium <i>tert</i>-Butoxide-Mediated Condensation Cascade Reaction: Transition Metal-Free Synthesis of Multisubstituted Aryl Indoles and Benzofurans
作者:Pengfei Yang、Weiyan Xu、Rongchao Wang、Min Zhang、Chunsong Xie、Xiaofei Zeng、Min Wang
DOI:10.1021/acs.orglett.9b01093
日期:2019.5.17
tert-butoxide-mediated condensation reactioninvolving a vinyl sulfoxide intermediate. Products are obtained from N- or O-benzyl benzaldehydes using dimethyl sulfoxide as a carbon source. The methodology features a wide functional group tolerance and transition metal-free environment. Preliminary mechanistic studies suggest that the reactioninvolves a tandem aldol reaction/Michaeladdition/dehydrosulfenylation/isomerization
Synthesis of 2,3-Disubstituted Indoles and Benzofurans by the Tandem Reaction of Rhodium(II)-Catalyzed Intramolecular C–H Insertion and Oxygen-Mediated Oxidation
作者:Hongjuan Shen、Junkai Fu、Hao Yuan、Jianxian Gong、Zhen Yang
DOI:10.1021/acs.joc.6b00611
日期:2016.11.4
A highly effective and straightforward method to construct a wide range of functionalized 2,3-disubstituted indoles has been developed. The method involves the tandem reaction of rhodium(II)-catalyzed denitrogenative annulation of triazole-based benzyl anilines and oxygen-mediated oxidative aromatization. The developed method can also be used to synthesize 2,3-disubstituted benzofurans by replacing