Cobalt-Catalyzed Selective Synthesis of Isoquinolines Using Picolinamide as a Traceless Directing Group
作者:Changsheng Kuai、Lianhui Wang、Bobin Li、Zhenhui Yang、Xiuling Cui
DOI:10.1021/acs.orglett.7b00702
日期:2017.4.21
first been employed as a traceless directing group for the cobalt-catalyzed oxidative annulation of benzylamides with alkynes to synthesize isoquinolines throughC–H/N–H bonds activation. Oxygen is used as a terminal oxidant. This protocol exhibits good functional group tolerance and excellent regioselectivity. Both terminal and internalalkynes can be efficiently applied to this catalytic system as substrates
Rhodium‐Catalyzed Copper‐Assisted Intermolecular Domino C−H Annulation of 1,3‐Diynes with Picolinamides: Access to Pentacyclic π‐Extended Systems
作者:Ángel Manu Martínez、Inés Alonso、Nuria Rodríguez、Ramón Gómez Arrayás、Juan C. Carretero
DOI:10.1002/chem.201900162
日期:2019.4.17
reactivity of 1,3‐diynes in rhodium‐catalyzedoxidative annulation reactions has enabled the rapid assembly of extended π systems from readily available picolinamide derivatives. The process involves a double C−H bond activation and the iterative annulation of two 1,3‐diyne units, with each alkyne moiety engaged in an orchestrated insertion sequence with high regiocontrol, leading to the formation of five new
Cobalt-Catalyzed<i>ortho</i>-C−H Functionalization/Alkyne Annulation of Benzylamine Derivatives: Access to Dihydroisoquinolines
作者:Ángel Manu Martínez、Nuria Rodríguez、Ramón Gómez-Arrayás、Juan C. Carretero
DOI:10.1002/chem.201702283
日期:2017.8.25
A practical picolinamide-directed C−H functionalization/alkyne annulation of benzylaminederivatives enabling access to the previously elusive 1,4-dihydroisoquinoline skeleton was developed using molecular O2 as the sole oxidant and Co(OAc)2 as precatalyst. The method is compatible with both internal and terminal alkynes and shows high versatility and functional-group tolerance. Furthermore, full preservation
Tetramethyl Orthosilicate (TMOS) as a Reagent for Direct Amidation of Carboxylic Acids
作者:D. Christopher Braddock、Paul D. Lickiss、Ben C. Rowley、David Pugh、Teresa Purnomo、Gajan Santhakumar、Steven J. Fussell
DOI:10.1021/acs.orglett.7b03841
日期:2018.2.16
Tetramethyl orthosilicate (TMOS) is shown to be an effective reagent for direct amidation of aliphatic and aromatic carboxylic acids with amines and anilines. The amide products are obtained in good to quantitative yields in pure form directly after workup without the need for any further purification. A silyl ester as the putative activated intermediate is observed by NMR methods. Amidations on a
Traceless Directing Group Assisted Cobalt-Catalyzed C−H Carbonylation of Benzylamines
作者:Fei Ling、Chongren Ai、Yaping Lv、Weihui Zhong
DOI:10.1002/adsc.201700780
日期:2017.11.10
The first example of cobalt‐catalyzed C(sp2)−H carbonylation of benzylamines using a traceless directing group is reported, which was successfully applied to the synthesis of N−unprotected iso‐indolinones through direct C−H/N−H bonds activation. This protocol tolerates a variety of functional groups and provides a facile and efficient method for the formal synthesis of (+)‐garenoxacin.
报道了使用无痕导向基团的钴催化苄胺的C(sp 2)-H羰基羰基化的第一个实例,该实例已成功地用于通过直接CH / H / NH键活化而合成N-未保护的异吲哚啉酮。该方案可耐受多种官能团,并为(+)-加仑沙星的正式合成提供了一种简便而有效的方法。