Rh(III)-Catalyzed Regio- and Chemoselective [4 + 1]-Annulation of Azoxy Compounds with Diazoesters for the Synthesis of 2<i>H</i>-Indazoles: Roles of the Azoxy Oxygen Atom
作者:Zhen Long、Zhigang Wang、Danni Zhou、Danyang Wan、Jingsong You
DOI:10.1021/acs.orglett.7b00631
日期:2017.6.2
tandem C–H alkylation/intramolecular decarboxylative cyclization of azoxy compounds with diazoesters for the synthesis of 3-acyl-2H-indazoles is disclosed. The azoxy instead of the azo group enables a distinct approach for cyclative capture, leading to a [4 + 1]-annulation rather than a classic [4 + 2] manner. The azoxy oxygen atom is traceless after annulation, and further removal from the product is
(3 + 2)-Cycloaddition of Donor–Acceptor Cyclopropanes with Selenocyanate: Synthesis of Dihydroselenophenes and Selenophenes
作者:Anu Jacob、Peter G. Jones、Daniel B. Werz
DOI:10.1021/acs.orglett.0c03329
日期:2020.11.6
We present a Lewis-acid-catalyzed (3 + 2)-cycloaddition of donor–acceptor cyclopropanes and selenocyanate (as its tetramethylammonium salt) for the synthesis of dihydroselenophenes. The transformation proceeded with moderate to excellent yields and showed a high functional group tolerance. Further oxidation using DDQ delivered selenophenes.
Rh<sub>2</sub>(esp)<sub>2</sub>: An Efficient Catalyst for O-H Insertion Reactions of Carboxylic Acids into Acceptor/Acceptor Diazo Compounds
作者:Arianne C. Hunter、Kiran Chinthapally、Indrajeet Sharma
DOI:10.1002/ejoc.201600064
日期:2016.5
Rh2(esp)2 has been identified as a highly efficient catalyst for O–H insertion of carboxylic acids into acceptor/acceptor diazocompounds. The insertion reaction proceeds in CH2Cl2 within minutes at room temperature in excellent yields and accommodates carboxylic acids having varying functionalities including amino acids, free alcoholic and phenolic O–H, indole N–H, alkenes, alkynes, and substituted
(3+2)-Cycloaddition of Donor–Acceptor Cyclopropanes with Thiocyanate: A Facile and Efficient Synthesis of 2-Amino-4,5-dihydrothiophenes
作者:Daniel B. Werz、Anu Jacob、Philip Barkawitz、Ivan A. Andreev、Nina K. Ratmanova、Igor V. Trushkov
DOI:10.1055/a-1385-2385
日期:2021.6
An easy and efficient route to obtain 2-amino-4,5-dihydrothiophenes is presented. A formal (3+2)-cycloaddition of donor–acceptor cyclopropanes and ammonium thiocyanate catalyzed by Yb(OTf)3 delivers the desired products in good to excellent yields. A broad range of functional groups is tolerated during this process.
Direct C–H alkylation and indole formation of anilines with diazo compounds under rhodium catalysis
作者:Neeraj Kumar Mishra、Miji Choi、Hyeim Jo、Yongguk Oh、Satyasheel Sharma、Sang Hoon Han、Taejoo Jeong、Sangil Han、Seok-Yong Lee、In Su Kim
DOI:10.1039/c5cc07767b
日期:——
The rhodium(III)-catalyzed direct functionalization of aniline C-H bonds with [small alpha]-diazo compounds is described. These transformations provide the facile construction of ortho-alkylated anilines with diazo malonates or highly substituted indoles with...