Abstract:
An organic synthesis method in which a metal compound stable in water and functioning as a Lewis acid is used as a novel Lewis acid catalyst in a reaction system employing water as part or all of the solvent, wherein the compound gives a metal ion having a hydrolysis constant (pKh) of 4.3 to 10.1 and a water exchange rate constant (WERC) of 3.2x10?6 M-1sec-1¿ or larger.
Abstract:
A method for an aldol reaction in water, characterized in that an aldehyde and an silyl enol ether is reacted in water as a medium in the presence of a boronic acid represented by the general formula (1): R R BOH (1) wherein R and R are hydrocarbon groups which may be the same or different and may have a substituent, a surfactant and a Brfnsted acid. The method for an aldol reaction in water allows the production of a product with high selectivity in high yield by the use of a boron source in an catalytic amount.
Abstract:
The present invention provides a polysilane-supported transition metal catalysts or a polysilane/inorganic compound-supported transition metal catalysts, wherein various types of transition metals are supported by polysilane compounds, or combination of polysilanes and inorganic compounds. The catalysts of the present invention are hardly soluble in hydrocarbons and alcohols and are useful as catalysts in heterogeneous system for various organic synthetic reactions using the above solvents. Polysilanes supporting transition metals are easily crosslinkable by thermal treatment, microwave irradiation, UV irradiation or chemical methods such as hydrosilylation reaction and are changed to be insoluble in various solvents keeping high catalytic activity. Moreover, the stability and operability of polysilane-supported transition metal catalysts will be improved by the support thereof on inorganic compounds. These polysilane-supported transition metal catalysts show a high catalytic activity in hydrogenation reaction, hydrosilylation reaction, Heck reaction, Suzuki-Miyaura coupling reactions and the like. The catalyst is easily recoverable and reusable and the leakage of metals is extremely few.
Abstract:
An asymmetric reaction catalyst is obtained by mixing a pentavalent niobium compound and an optically active triol or tetraol having a binaphthol structure of R or S configuration, and the triol is represented by the following formula:
(wherein, Y is divalent hydrocarbon and R 1 is a hydrogen atom, a halogen atom, a trifluoromethyl group, or an alkyl group or alkoxy group having at most 4 carbons).
Abstract:
[PROBLEMS] To provide a novel method for the allylation of N-acylhydrazones by which enantioselectively allylated N-acylhydrazines can be efficiently obtained. [MEANS FOR SOLVING PROBLEMS] A method for the production of enantioselectively allylated N-acylhydrazines represented by the general formula [3]:
[wherein R° is an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, or -COOR 1 (wherein R 1 is a hydrocarbon group) ; R 2 is acyl; R 3 and R 4 are each hydrogen, or one of R 3 and R 4 is hydrogen and the other is a hydrocarbon group; and R 5 and R 6 are each independently hydrogen or a hydrocarbon group], characterized by reacting an N-acylhydrazone represented by the general formula [1]:
[wherein R 0 and R 2 are as defined above] with an allylating agent such as allyltrichlorosilane or crotyltrichlorosilane in the presence of a chiral phosphine oxide.
Abstract translation:[问题]提供N-酰腙的烯丙基化的新方法,通过该方法可以有效地获得对映选择性烯丙化的N-酰肼。 用于解决问题的手段制备由通式[3]表示的对映选择性烯丙化N-酰肼的方法:[其中R'是任选取代的烃基,任选取代的杂环基或-COOR 1(其中R 1是烃基); R 2是酰基; R 3和R 4各自为氢,R 3和R 4中的一个为氢,另一个为烃基; 并且R 5和R 6各自独立地为氢或烃基],其特征在于使由通式[1]表示的N-酰腙:[其中R 0和R 2如上定义]与烯丙基化试剂如 烯丙基三氯硅烷或巴豆基三氯硅烷在手性氧化膦存在下进行。
Abstract:
Febrifugine represented by formula (A) and isofebrifugine represented by formula (B), having an extremely potent activity on Plasmodium falciparum; and total synthesis routes permitting efficient mass production of both.
Abstract:
A novel polymer-supported arene-ruthenium complex represented by the following formula: , wherein A represents an organic polymer with a side chain containing an aromatic ring coordinated to Ru, X 1 and X 2 represent the same or different halogen atoms, and R represents a hydrocarbon group that may have a substituent is provided for use as a catalyst. This novel polymer-supported arene-ruthenium complex and catalyst thereof can be produced by a simple process, are stable and easy to recover, have a high catalytic activity, and can be used for various organic synthesis reactions. Novel methods for an organic synthesis reaction such as ring-opening metathesis reaction of an olefin compound and reduction of a carbonyl group, using the catalyst are provided.
Abstract:
An intramolecular [3+2] cycloaddition reaction of a hydrazone is carried out under a mild condition with a high stereoselectivity and yield by reacting a hydrazone derivative in the presence of an asymmetric catalyst system obtained by mixing a zirconium alkoxide represented by the following formula (I):
Zr(OR) 4 (I)
(wherein R is a hydrocarbon group which may have a substituent) with a binaphthol derivative represented by the following formula (II): (wherein Y 1 and Y 2 are each identical or different and denote a hydrogen atom or a halogen atom, and at least one of Y 1 and Y 2 denotes a halogen atom).