Organometallics p. 4358 - 4379 (2018)
Update date:2022-08-06
Topics:
Nguyen, Hiep N.
Lee, Hyeunjoo
Aud?rsch, Stephan
Reznichenko, Alexander L.
Nawara-Hultzsch, Agnieszka J.
Schmidt, Bernd
Hultzsch, Kai C.
The series of novel 3,3′-bis(trisarylsilyl)- and 3,3′-bis(arylalkylsilyl)-substituted binaphtholate rare-earth-metal complexes 2a-i (SiR3 = Si(o-biphenylene)Ph (a), SiCyPh2 (b), Si-t-BuPh2 (c), Si(i-Pr)3 (d), SiCy2Ph (e), Si(2-tolyl)Ph2 (f), Si(4-t-Bu-C6H4)3 (g), Si(4-MeO-C6H4)Ph2 (h), SiBnPh2 (i)) have been prepared via arene elimination from [Ln(o-C6H4CH2NMe2)3] (Ln = Y, Lu) and the corresponding 3,3′-bis(silyl)-substituted binaphthol. The complexes exhibit high catalytic activity in the hydroamination/cyclization of aminoalkenes, with activities exceeding 1000 h-1 for (R)-2f-Ln, (R)-2g-Ln, and (R)-2h-Ln in the cyclization of 2,2-diphenylpent-4-enylamine (3a) at 25 °C, while the rigid dibenzosilole-substituted complexes (R)-2a-Ln and the triisopropylsilyl-substituted complexes (R)-2d-Ln exhibited the lowest activity in the range of 150-270 h-1. Catalysts (R)-2b-Lu, (R)-2c-Lu, (R)-2f-Lu, and (R)-2i-Lu provide the highest selectivities for the majority of the substrates, while the yttrium congeners are usually less selective. The highest enantioselectivities of 96% ee were observed using (R)-2a-Lu and (R)-2c-Lu in the cyclization of (4E)-2,2,5-triphenylpent-4-enylamine (9). The reactions show apparently zero-order rate dependence on substrate concentration and first-order rate dependence on catalyst concentration, with some reactions exhibiting a slightly accelerated rate at high conversion due to a shift in the equilibrium between a less active, higher coordinate catalyst species in favor of a more active, lower coordinate species as a result of weaker binding of the hydroamination product in comparison to the aminoalkene substrate. The shift in equilibrium from the higher to the lower coordinate species is also entropically favored at elevated temperatures, which results in an unusual increase in selectivity in the cyclization of 2,2-dimethylpent-4-enylamine (3d), presumably due to a higher selectivity of the lower coordinate catalyst species. All binaphtholate yttrium complexes, except (R)-2a-Y, are catalytically active in the intermolecular hydroamination of benzylamines with terminal alkenes. The highest selectivity of 66% ee was observed for the reaction of benzylamine with 4-phenyl-1-butene using (R)-2h-Y at 110 °C.
View MoreRugao Jinling Chemical Co., Ltd.(expird)
Contact:0086-513-68005586
Address:Lianluo new village huangshi town Rugao city Jiangsu Province.
Contact:+86-571-87010026
Address:202, Zhenhua Road,
website:http://www.win-winchemical.com
Contact:0086-577-64498589
Address:6F, No. 396 Xingping Road, Longwan Industrial Zone, Wenzhou City, Zhejiang, 325000 P.R.China
Shandong Jincheng Zhonghua Bio-pharmaceutical Co.,Ltd
Contact:+86-533-5415882
Address:Zichuan Economic Development Zone,Zibo City,Shandong Province,China
Jiangsu Feymer Technology Co., Ltd.
Contact:+86-512-58110132
Address:Fenghuang Town, Zhangjiagang City, Jiangsu Province, China
Doi:10.1021/ol102844q
(2011)Doi:10.1002/asia.201402865
(2014)Doi:10.1002/chem.201201214
(2012)Doi:10.1016/S0040-4039(00)99405-X
(1989)Doi:10.1590/S0103-50532010000100008
(2010)Doi:10.1021/acs.orglett.1c02151
(2021)