873066-23-0Relevant articles and documents
Method for preparing aminoarylborane compounds or derivatives thereof
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, (2015/06/17)
The present invention provides a process for the preparation of aminoarylborane compounds and derivatives thereof comprising a step of arylation by reacting an aryl chloride with an aminoborane compound in the presence of a catalytic system. Typically, th
Mn-catalyzed aromatic C-H alkenylation with terminal alkynes
Zhou, Bingwei,Chen, Hui,Wang, Congyang
supporting information, p. 1264 - 1267 (2013/03/14)
The first manganese-catalyzed aromatic C-H alkenylation with terminal alkynes is described. The procedure features an operationally simple catalyst system containing commercially available MnBr(CO)5 and dicyclohexylamine (Cy2NH). The reaction occurs readily in a highly chemo-, regio-, and stereoselective manner delivering anti-Markovnikov E-configured olefins in high yields. Experimental study and DFT calculations reveal that (1) the reaction is initiated by a C-H activation step via the cooperation of manganese and base; (2) manganacycle and alkynylmanganese species are the key reaction intermediates; and (3) the ligand-to-ligand H-transfer and alkynyl-assisted C-H activation are the key steps rendering the reaction catalytic in manganese.
Enantioselective synthesis of cis-1,2-disubstituted cyclopentanes and cyclohexanes by Suzuki-Miyaura cross-coupling and iridium-catalyzed asymmetric hydrogenation
Schumacher, Andreas,Schrems, Marcus G.,Pfaltz, Andreas
supporting information; experimental part, p. 13502 - 13509 (2012/01/05)
A series of 1,2-disubstituted cyclohexene derivatives was prepared through Suzuki-Miyaura cross-coupling of 2-bromo-1-cyclohexenecarbaldehyde or 2-carbomethoxy-1-cyclohexen-1-yl triflate with arylboronates. These tetra-substituted cyclic alkenes were subjected to Ir-catalyzed asymmetric hydrogenation. In this way cis-1-methoxymethyl-2-arylcyclohexanes were obtained in high yield with excellent enantio- and diastereoselectivities (up to >99%ee, >99%cis) by using phosphinomethyloxazolines as ligands. Asymmetric hydrogenation of analogous cyclopentene derivatives, prepared by Suzuki-Miyaura cross-coupling, proved to be more difficult and proceeded with lower enantioselectivities of up to 88%ee. The synthetic potential of this cross-coupling/asymmetric-hydrogenation strategy was demonstrated by an enantioselective route to chiral hexahydrofluorenones. Alkene interest: Starting from arylboronates, a variety of cyclic, tetra-substituted olefins was prepared by Suzuki-Miyaura cross-coupling (see scheme). Subsequent Ir-catalyzed asymmetric hydrogenation with phosphanylmethyloxazoline ligand complexes led to cis-disubstituted cycloalkane derivatives in high yield and excellent enantio- and distereoselectivities. Copyright
