A Highly Stereoselective Synthesis of α-Carbethoxy-α,β-unsaturated Phosphonates Mediated by Tri-n-Butylarsine
摘要:
A highly stereoselective synthesis of alpha-carbethoxy-alpha,beta-unsaturated phosphonates in 71-92% yield mediated by tri-n-butylarsine under neutral condition is described.
A Catalytic Michael/Horner-Wadsworth-Emmons Cascade Reaction for Enantioselective Synthesis of Thiochromenes
作者:Abhijnan Ray Choudhury、Santanu Mukherjee
DOI:10.1002/adsc.201300281
日期:2013.7.8
A catalyticenantioselective sulfa‐Michael/Horner–Wadsworth–Emmonsreactioncascade has been developed, taking advantage of phosphonate as an electrophilic activator and a traceless binding site. Using a chiral bifunctional urea derivative as the catalyst, a variety of aryl and heteroaryl substituted thiochromenes was obtained in excellent yield with a high level of enantioselectivity.
In the presence of titanium tetrachloride and an organic base in tetrahydrofurane, triethyl phosphonoacetic acid undergoes condensation with aliphatic and aromatic aldehydes and aromatic ketones to yield the corresponding triethyl alkylidene and arylidene phosphonoacetic acids respectively. Tetraalkyl methylenediphosphonates and aromatic or aliphatic α-branched aldehydes react under identical conditions
malononitrile to vinyl phosphonates was accomplished by hydrogen bond-enhanced bifunctional halogen bond (XB) catalysis. NMR titration experiments were used to demonstrate that halogen bonding, with the support of hydrogen-bonding, played a key role in the activation of the Michael acceptors through the phosphonate group. This is the first example of the use of XBs for the activation of organophosphorus
A compound represented by the formula (I)
1
wherein one of R
1
and R
2
is a hydrogen atom or a substituent and the other is an optionally substituted cyclic group;
W is a bond or a divalent aliphatic hydrocarbon group;
Y is a group of the formula: —OR
3
(wherein R
3
is a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group or an optionally substituted acyl group) or an optionally esterified or amidated carboxyl group, or a salt thereof or a prodrug thereof has a superior insulin secretion promoting action and a hypoglycemic action and shows low toxicity. Therefore, the compound is useful as a pharmaceutical agent, particularly as an agent for the prophylaxis or treatment of diabetes and diabetic complications, and the like.
A compound represented by the formula (I)
wherein one of R1 and R2 is a hydrogen atom or a substituent and the other is an optionally substituted cyclic group;
W is a bond or a divalent aliphatic hydrocarbon group;
Y is a group of the formula: -OR3 (wherein R3 is a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group or an optionally substituted acyl group) or an optionally esterified or amidated carboxyl group, or a salt thereof or a prodrug thereof has a superior insulin secretion promoting action and a hypoglycemic action and shows low toxicity. Therefore, the compound is useful as a pharmaceutical agent, particularly as an agent for the prophylaxis or treatment of diabetes and diabetic complications, and the like.
由式(I)代表的化合物
其中 R1 和 R2 中的一个是氢原子或取代基,另一个是任选取代的环状基团;
W 是键或二价脂族烃基;
Y 是式中的一个基团:-OR3(其中 R3 是氢原子、任选取代的烃基、任选取代的杂环基或任选取代的酰基)或任选酯化或酰胺化的羧基,或其盐或其原药具有优异的促进胰岛素分泌作用和降血糖作用,且毒性低。因此,该化合物可用作药物制剂,特别是用于预防或治疗糖尿病和糖尿病并发症等。