56658-06-1Relevant academic research and scientific papers
Sulfoxide ligand metal catalyzed oxidation of olefins
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Page/Page column 111, (2019/05/09)
The enantioselective synthesis of isochroman motifs has been accomplished via Pd(II)-catalyzed allylic C—H oxidation from terminal olefin precursors. Critical to the success of this goal was the development and utilization of a novel chiral aryl sulfoxide-oxazoline (ArSOX) ligand. The allylic C—H oxidation reaction proceeds with the broadest scope and highest levels asymmetric induction reported to date (avg. 92% ee, 13 examples ≥90% ee). Additionally, C(sp3)-N fragment coupling reaction between abundant terminal olefins and N-triflyl protected aliphatic and aromatic amines via Pd(II)/sulfoxide (SOX) catalyzed intermolecular allylic C—H amination is disclosed. A range of 52 allylic amines are furnished in good yields (avg. 76%) and excellent regio- and stereoselectivity (avg. >20:1 linear:branched, >20:1 E:Z). For the first time, a variety of singly activated aromatic and aliphatic nitrogen nucleophiles, including ones with stereochemical elements, can be used in fragment coupling stiochiometries for intermolecular C—H amination reactions.
C-H to C-N Cross-Coupling of Sulfonamides with Olefins
Ma, Rulin,Christina White
, p. 3202 - 3205 (2018/03/13)
Cross-coupling of nitrogen with hydrocarbons under fragment coupling conditions stands to significantly impact chemical synthesis. Herein, we disclose a C(sp3)-N fragment coupling reaction between terminal olefins and N-triflyl protected aliphatic and aromatic amines via Pd(II)/SOX (sulfoxide-oxazoline) catalyzed intermolecular allylic C-H amination. A range of (56) allylic amines are furnished in good yields (avg. 75%) and excellent regio- and stereoselectivity (avg. >20:1 linear:branched, >20:1 E:Z). Mechanistic studies reveal that the SOX ligand framework is effective at promoting functionalization by supporting cationic π-allyl Pd.
Nickel(II) complexes bearing phosphinooxazoline ligands: Synthesis, structures and their ethylene oligomerization behaviors
Tang, Xiubo,Zhang, Dongheng,Jie, Suyun,Sun, Wen-Hua,Chen, Jiutong
, p. 3918 - 3928 (2007/10/03)
A series of Ni(II) complexes 4a-f ligated by the unsymmetrical phosphino-oxazolines (PHOX) were synthesized and characterized by elemental analysis and IR spectroscopy, and the structures of complexes 4c-4e were confirmed by the X-ray crystallographic analysis. All derivatives showed distorted tetrahedron geometry by the nickel center and coordinative atoms. Upon activation with methylaluminoxane (MAO) or Et2AlCl, these complexes exhibited considerable to high activity of ethylene oligomerization. The ligands environments and reaction conditions significantly affect their catalytic activities, while the highest oligomerization activity (up to 1.18 × 106 g ? mol-1(Ni) ? h-1) was observed for 4d at 20 atm of ethylene. Incorporation of 2-4 equivalents of PPh 3 as auxiliary ligands in the 4a-f/MAO catalytic systems led to higher activity and longer catalytic lifetime.
Synthesis of spiro[isobenzofuran 1(3H),4' piperidines] as potential central nervous system agents
Bauer,Duffy,Hoffman,Klioze,Kosley Jr.,McFadden,Martin,Ong
, p. 1315 - 1324 (2007/10/05)
Synthesis of 1' methyl 3 phenylspiro[isobenzofuran 1(3H),4' piperidine] (7a, HP 365) and the demethyl analogue 9a (HP 505) was prompted by recognition of an aminoalkyl(aryl)isobenzofuran moiety common to the antidepressants talopram (Lu 3-010) and trans 10,11 dihydro 5,10 epoxy 5 [3 (methylamino)propyl] 5H dibenzo[a,d]cyclohepten 11 ol (MK-940). Convenient laboratory synthesis of 7a was provided by lithiation of 2 bromobenzhydryl methyl ether, followed by addition of 1 methyl 4 piperidone and acid catalyzed cyclization. N Dealkylation by standard methods afforded 9a. Synthesis of analogues was stimulated by discovery of marked inhibition of tetrabenazine induced ptosis for lead compounds 7a and 9a. Optimal antitetrabenazine activity is associated with the 3 phenylspiro[isobenzofuran 1(3H),4' piperidine] moiety where nitrogen is basic. Modification of this moiety by introduction of large nitrogen substituents or a C-3 substituent > H significantly reduced antitetrabenazine activity. A series of analogue with aromatic substituents was investigated; however, few of these compounds were significantly more active than 7a and 9a. Compound 9a was selected for additional studies.
