Abstract:A direct three‐component reaction of aldehydes, amines and diaryl phosphites was catalyzed by a zinc(II) complex of 1,3‐bis(imidazolin‐2‐ly)pyridine (pybim) giving the corresponding α‐aminophosphonates in good yield with good enantioselectivity. The reaction was applied to a wide variety of aromatic aldehydes to give products with excellent yields (up to 99%) and enantiomeric excesses (up to 93% ee).
“…In the same year, Shibata et al. developed direct enantioselective three‐component Kabachnik–Fields reaction of aldehydes, p ‐aminophenol and diaryl phosphites catalyzed by a chiral zinc(II) complex of C 2 ‐symmetric pybim ligand 274 174. As shown in Scheme , a range of α‐aminophosphonates 275a – h could be achieved in almost quantitative yields in all cases of substrates studied and high enantioselectivities of up to 93% ee .…”
Chronic kidney disease (CKD) is a common cause of end-stage renal disease. Antihypertensive agents are used clinically to inhibit the progression of CKD, but cannot prevent eventual renal failure. This study investigated the effect of Tanshinone IIA, an active component of Salvia miltiorrhiza, in rats suffering from CKD induced by 5/6 nephrectomy. After development of renal insufficiency, the rats were treated with Tanshinone IIA (10 mg/kg) for 8 weeks. Serum creatinine, angiotensin II (Ang II), transforming growth factor β1 (TGF-β1) and collagen IV levels were significantly reduced in Tanshinone IIA treated rats compared with a control group. In addition, Tanshinone IIA suppressed increases in urinary protein excretion in CKD rats. These findings suggest that chronic oral administration of Tanshinone IIA can improve renal dysfunction associated with CKD.
“…In the same year, Shibata et al. developed direct enantioselective three‐component Kabachnik–Fields reaction of aldehydes, p ‐aminophenol and diaryl phosphites catalyzed by a chiral zinc(II) complex of C 2 ‐symmetric pybim ligand 274 174. As shown in Scheme , a range of α‐aminophosphonates 275a – h could be achieved in almost quantitative yields in all cases of substrates studied and high enantioselectivities of up to 93% ee .…”
Chronic kidney disease (CKD) is a common cause of end-stage renal disease. Antihypertensive agents are used clinically to inhibit the progression of CKD, but cannot prevent eventual renal failure. This study investigated the effect of Tanshinone IIA, an active component of Salvia miltiorrhiza, in rats suffering from CKD induced by 5/6 nephrectomy. After development of renal insufficiency, the rats were treated with Tanshinone IIA (10 mg/kg) for 8 weeks. Serum creatinine, angiotensin II (Ang II), transforming growth factor β1 (TGF-β1) and collagen IV levels were significantly reduced in Tanshinone IIA treated rats compared with a control group. In addition, Tanshinone IIA suppressed increases in urinary protein excretion in CKD rats. These findings suggest that chronic oral administration of Tanshinone IIA can improve renal dysfunction associated with CKD.
“…So, we propose the plausible mechanism for the synthesis of N,S ‐acetals by using Zn( L ‐Pro) 2 as catalyst for thiol addition to N ‐Boc imine (Scheme ). Is noteworthy that this supposed mechanism is based on Oliveira and Shibata reports in which they described a zinc octahedral intermediate. Our conclusion relies on the intermediate 4.…”
Herein we present a new, highly efficient (60‐ 98 %), low cost and easy procedure for the addition of thiols to N‐Boc imines catalyzed by [Zn(L‐Pro)2] aiming the construction of some different N,S‐acetals by using a low catalytic loading (1 % mol) in short reactions time and under mild conditions.
“…In the same year, Shibata et al developed direct enantioselective three-component Kabachnik−Fields reaction of aldehydes, p-aminophenol and diarylphosphites catalyzed by a chiral zinc(II) complex of C 2symmetric pybim ligand 274. [174] As shown in Scheme 74, a range of -aminophosphonates 275a-h could be achieved in almost quantitative yields in all cases of substrates studied and high enantioselectivities of up to 93% ee. Although the scandium-catalyzed process described above by Feng et al employed a lower catalyst loading (5 mol% instead of 10 mol%) and a milder reaction temperature (-20°C instead of -50°C) to occur in comparison with this zinc-catalyzed process, the later provided both higher yields and enantioselectivities.…”
International audienceSince the first definition of domino reactions by Tietze in 1993, an explosive number of these fascinating reactions have been developed, allowing easily building complex chiral molecular architectures from simple materials to be achieved in a single step. Even more interesting, the possibility to join two or more reactions in one asymmetric domino process catalyzed by chiral metal catalysts has rapidly become one challenging goal for chemists, due to economical advantages, such as avoiding costly protecting groups and time-consuming purification procedures after each step. The explosive development of enantioselective metal-catalyzed domino including multicomponent reactions is a consequence of the considerable impact of the advent of asymmetric transition-metal catalysis. This review aims to update the last developments of enantioselective one-, two-and multicomponent domino reactions mediated by chiral metal catalysts, covering the literature since the beginning of 2006
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