The ruthenium-catalyzed C–H functionalization of enamides with isocyanates: easy entry to pyrimidin-4-ones
作者:Pengfei Shi、Song Li、Lu-Min Hu、Cong Wang、Teck-Peng Loh、Xu-Hong Hu
DOI:10.1039/c9cc03612a
日期:——
Ruthenium-catalyzedheteroannulation between enamides and isocyanates has been realized as a complementary approach to conventional strategies for the synthesis of pyrimidin-4-ones. High step- and atom-economy was achieved for the rapid construction of such privileged scaffolds, which are found in a multitude of pharmaceutical compounds. The generality and practicability of this transformation were
Selective Dehydrogenative Acylation of Enamides with Aldehydes Leading to Valuable β-Ketoenamides
作者:Rui-Hua Liu、Zhen-Yao Shen、Cong Wang、Teck-Peng Loh、Xu-Hong Hu
DOI:10.1021/acs.orglett.9b04495
日期:2020.2.7
We have presented a unique example of dehydrogenative acylation of enamides with aldehydes enabled by an earth-abundant iron catalyst. The protocol provides the straightforward access to valuable β-ketoenamides with ample substrate scope and excellent functional group tolerance. Notably, distinct C-H acylation of enamide rather than at N-H moiety site occurs with absolute Z-selectivity was observed
Direct Titanium-Mediated Conversion of Ketones into Enamides with Ammonia and Acetic Anhydride
作者:Jonathan T. Reeves、Zhulin Tan、Zhengxu S. Han、Guisheng Li、Yongda Zhang、Yibo Xu、Diana C. Reeves、Nina C. Gonnella、Shengli Ma、Heewon Lee、Bruce Z. Lu、Chris H. Senanayake
DOI:10.1002/anie.201107601
日期:2012.2.6
A one‐step conversion of ketones into N‐acetyl enamides was developed. The process employs safe and inexpensive reagents, proceeds under mild conditions, and tolerates diverse functional groups. The addition of edte (N,N,N′,N′‐tetrakis(2‐hydroxyethyl)ethylenediamine) prior to workup enables water solubilization of Ti alkoxides and allows a simple extractive workup.
2, 3-Bis(dialkylphosphino)pyrazine derivative, process of producing the same, and metal complex having the same as ligand
申请人:Imamoto Tsuneo
公开号:US20070021610A1
公开(公告)日:2007-01-25
An optically active 2,3-bis(dialkylphosphino)pyrazine derivative represented by formula (1) is disclosed. The pyrazine derivative is preferably a quinoxaline derivative represented by formula (2). In formula (1) and (2), R
1
is preferably a t-butyl or adamantyl group, and R
2
is preferably a methyl group.
wherein R
1
is a substituted or unsubstituted, straight chain or branched alkyl group having 2 to 10 carbon atoms; R
2
is a substituted or unsubstituted, straight chain or branched alkyl group having fewer carbon atoms than R
1
; and R
3
and R
4
, which may be the same or different, are each a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, or R
3
and R
4
are taken together to form a saturated or unsaturated ring.
wherein R
1
and R
2
are as defined above; and R
5
is a monovalent substituent.
An Air-Stable P-Chiral Phosphine Ligand for Highly Enantioselective Transition-Metal-Catalyzed Reactions
作者:Tsuneo Imamoto、Keitaro Sugita、Kazuhiro Yoshida
DOI:10.1021/ja053458f
日期:2005.8.1
A new P-chiralphosphineligand, (R,R)-2,3-bis(tert-butylmethylphosphino)quinoxaline, has been prepared by the reaction of enantiomerically pure tert-butylmethylphosphine-borane with 2,3-dichloroquinoxaline. This ligand, in contrast to most of the previously reported P-chiralligands, is an air-stable solid and exhibits excellent enantioselectivities in both Rh-catalyzed asymmetric hydrogenations and