BoPhoz类膦-氨基膦配体在Rh-催化β-脱氢氨基酸酯的不对称氢化反应中的应用

将BoPhoz类膦-氨基膦配体应用在Rh-催化β-脱氢氨基酸酯的不对称氢化反应中,考察了配体结构及反应条件对反应结果的影响,并在优化的条件下研究了各种底物的适用范围,产物的对映选择性达81％ee．     

苯乙胺衍生的手性膦-亚磷酰胺酯配体在Rh-催化α-烯醇酯膦酸酯的不对称氢化反应中的应用

将苯乙胺衍生的手性膦-亚磷酰胺酯配体应用在Rh-催化α-烯醇酯膦酸酯的不对称氢化反应中,考察了配体结构及反应条件对反应结果的影响,并在优化的条件下研究了各种底物的适用范围,产物的对映选择性最高〉99%ee.     

苯乙胺衍生的手性膦-亚磷酰胺酯配体在Rh-催化a-烯醇酯膦酸酯的不对称氢化反应中的应用

将苯乙胺衍生的手性膦-亚磷酰胺酯配体应用在Rh-催化α-烯醇酯膦酸酯的不对称氢化反应中,考察了配体结构及反应条件对反应结果的影响,并在优化的条件下研究了各种底物的适用范围,产物的对映选择性最高>99%ee.     

双膦配体修饰铑催化乙酸乙烯酯氢甲酰化反应(英文)

研究了双膦配体对铑催化的乙酸乙烯酯氢甲酰化反应的促进作用,结果表明,在优化反应条件下,以双膦化合物2,2’-二(二苯膦甲基)-1,1’-联苯(BISBI)为配体时,铑催化乙酸乙烯酯氢甲酰化反应的TOF(转化频率)值达到4000h1,生成2-乙酰氧基丙醛的选择性99%.当在较温和的条件下Rh/BISBI催化乙酸乙烯酯氢甲酰化反应较长时间时TON(转化数)值达到9200,成醛率超过90%,2-乙酰氧基丙醛选择性仍保持99%.     

1,2-二苯基乙烯基膦钯(Ⅱ)催化的 Sonograshira交叉偶联反应

合成了含有大位阻和富电子膦配体的1,2-二苯基乙烯基膦配体, 并研究了以1,2-二苯基乙烯基膦配体和二氯化二苯腈合钯(Ⅱ)为催化剂催化的Sonograshira交叉偶联反应.     

手性膦烯配体在铑催化的芳基硼酸对β-芳基-α,β-不饱和磺酸酯不对称共轭加成反应中的应用

报道了手性膦烯配体在金属铑催化的芳基硼酸对β-芳基-α,β-不饱和磺酸酯不对称共轭加成中的应用.经过系统的反应条件筛选和配体结构优化,发现含手性1,1'-联-2-萘酚骨架的膦烯配体L7与Rh(I)形成的催化剂可以高对映选择性地实现β-芳基-α,β-不饱和磺酸酯化合物的不对称1,4-加成反应.此反应体系条件温和,底物普适性广,并取得了较高的收率(up to 95%)和优秀的对映选择性(up to 99%ee),为合成手性偕二芳基取代的磺酸酯类化合物提供了一种新方法.     

新型双膦配体的合成及其在2-丁烯氢甲酰化反应中的应用

合成了以联苯为骨架,以吲哚为取代基的双膦配体,并研究了该配体与Rh(acac)(CO)2原位生成的催化剂在2-丁烯氧甲酰化反应中的催化性能.考察了膦/铑比、反应温度、反应压力以及2-丁烯与Rh(acae)(CO)2摩尔比等因素对反应活性及区域选择性的影响.结果表明,在60℃反应时,醛的正异比高达28.5;当压力为2.0...     

一种新型双膦亚磷酸酯配体的合成及在1-己烯氢甲酰化反应中的应用

以4,4'-二羟基二苯丙烷和2,4-二叔丁基苯酚为原料合成了一种新型双膦亚磷酸酯配体,并用此配体和Rh(acac)(CO)2原位形成的催化体系催化1-己烯的氢甲酰化反应.系统考察了反应温度、压力、P/Rh和溶剂四种反应参数对催化体系的催化性能影响.选择了最佳的反应条件,在铑浓度为0.75×10-3mol/L、P/Rh比为10、温度100℃、压力(H2/CO=1)2.0MPa的条件下反应1.0h,在溶剂甲苯中1-己烯的转化率可达到100%,醛选择性为98.7%,TOF为3498.6h-1.在相同的条件下与以三苯基膦和单膦亚磷酸三(2,4-二叔丁基苯基)酯为配体的铑催化剂相比较,以新型双膦亚磷酸酯为配体的铑催化剂的催化活性是PPh3的1.6倍,而与亚磷酸三(2,4-二叔丁基苯基)酯的催化活性相当.     

面手性二芳基膦-噁唑啉配体的开发及其在不对称催化反应中的应用

膦-噁唑啉配体形成的催化剂具有出色的催化活性和对映选择性, 被广泛应用于各种不对称催化反应中. 具有面手性的膦-噁唑啉配体是其中重要的一类. 综述了面手性二芳基膦-噁唑啉配体的开发, 并按反应类型介绍了它们在不对称催化反应中的应用.     

钴—膦催化烯烃羰化的新反应

报道了在钴-膦催化剂和质子酸的存在下,烯烃与一氧化碳及乙醇或氢气生成酯、醛和缩醛的实验结果,并考察了不同的膦配体对反应的影响,以及生成的酯、醛和缩醛的比例如何随着反应条件的改变而改变。     

Enantioselective synthesis of beta2-amino acids via Rh-catalyzed asymmetric hydrogenation with BoPhoz-type ligands: important influence of an N-H proton in the ligand on the enantioselectivity

A series of BoPhoz-type ligands were successfully applied in the rhodium-catalyzed asymmetric hydrogenation of a number of beta-substituted or unsubstituted alpha-(phthalimidomethyl)acrylates, affording good to excellent enantioselectivities. The results suggested that the presence of an N-H proton in the BoPhoz backbone could significantly improve the enantioselectivity, and ligand (Sc,Rp)-1d, bearing two CF3-groups in the 3,5-position of the phenyl ring of aminophosphino moiety, showed the highest enantioselectivity.     

Readily available chiral phosphine–aminophosphine ligands derived from 1-phenylethylamine for Rh-catalyzed enantioselective hydrogenations

A series of new chiral phosphine–aminophosphine ligands have been prepared via a two- or three-step transformation from commercially available and inexpensive (S)-1-phenylethylamine, and successfully used in the rhodium-catalyzed asymmetric hydrogenation of various enamides, β-dehydroamino acid esters, and dimethyl itaconate. The results show that the ligand structure plays an important influence on both the reactivity and enantioselectivity. Ligand 2d bearing a N–H proton and two F-atoms on the 3,5-positions of the phenyl ring of the aminophosphino moiety was most effective for the hydrogenation of enamides and (Z)-β-aryl-β-(acylamino)acrylates, whereas ligand 1b showed the highest enantioselectivities in the hydrogenation of (Z)-β-alkyl-β-(acylamino)acrylates and dimethyl itaconate.     

Highly effective chiral ortho-substituted BINAPO ligands (o-BINAPO): applications in Ru-catalyzed asymmetric hydrogenations of beta-aryl-substituted beta-(acylamino)acrylates and beta-keto esters

A novel family of chiral ortho-substituted BINAPO ligands (o-BINAPO) were synthesized from BINOL, and their Ru complexes were highly efficient catalysts for asymmetric hydrogenation of beta-aryl-substituted beta-(acylamino)acrylates and beta-aryl-substituted beta-keto esters. The Ru-bisphosphinite catalysts can tolerate an E/Z mixture of beta-aryl-substituted beta-(acylamino)acrylates. These highly enantioselective hydrogenations provide a useful way to prepare beta-aryl-substituted beta-amino acids and beta-hydroxyl acids.     

Ru-catalyzed highly enantioselective hydrogenation of beta-alkyl-substituted beta-(acylamino)acrylates

Highly enantioselective hydrogenation of beta-alkyl-substituted (E)-beta-(acylamino)-acrylates catalyzed by Ru((R)-Xyl-P-Phos)(C(6)H(6))Cl(2) complex (cat. 1c) was achieved in up to 99.7% ee. Moderate to good enantioselectivities in the hydrogenation of corresponding (Z)-isomers in the presence of [Rh((R)-Xyl-P-Phos)(COD)]BF(4) (cat. 2c) were also obtained. The results demonstrated that the electronic and steric properties of the dipyridylphosphine ligands as well as the different transition metal ions have significant influences on the catalytic properties in the hydrogenation of beta-(acylamino)acrylates.     

A novel class of P-O monophosphite ligands derived from D-mannitol: broad applications in highly enantioselective Rh-catalyzed hydrogenations

We report on a new class of P-O monophosphite ligands (designated 3a-k) with a double six-membered-ring backbone onto which are attached additional groups and on applications of their Rh complexes in the hydrogenation of enamides, alpha-dehydroamino acid esters, dimethyl itaconate, and beta-(acylamino)acrylates. Our results demonstrate that the Rh complexes with ligands 3a-k exhibit high enantioselectivity and reactivity in asymmetric hydrogenation reactions. An ee value of up to 98.0% was obtained for the hydrogenation of alpha-dehydroamino acid esters, and the ee values were all over 99% for the other three types of substrate, with a turnover number of up to 5000.     

Highly efficient synthesis of chiral beta-amino acid derivatives via asymmetric hydrogenation

The Rh-TangPhos complex is an efficient hydrogenation catalyst for making chiral beta-amino acid derivatives. With the Rh-TangPhos system, high enantioselectivities (up to 99.6%) and turnover numbers have been obtained in the hydrogenation of E/Z isomeric mixtures of both beta-alkyl and beta-aryl beta-(acylamino)acrylates. [reaction: see text]     

Highly enantioselective rhodium-catalyzed hydrogenation of beta-dehydroamino acid derivatives using monodentate phosphoramidites

New and very easily accessible monodentate phosphoramidite ligands have been developed that lead to excellent ee's and full conversions in the hydrogenation of (E)- and (Z)-beta-dehydroamino acid derivatives with both aliphatic and aromatic side chains. Particularly, two different catalytic systems were established for (E)-beta-(acylamino)acrylates (98-99% ee) and (Z)-beta-(acylamino)acrylates (92-95% ee) based on phosphoramidites 2 and 3, respectively.     

Enantioselective hydrogenation of tetrasubstituted olefins of cyclic beta-(acylamino)acrylates

Hydrogenation of a series of cyclic beta-(acylamino)acrylates with tetrasubstituted olefins has been accomplished successfully with the use of Ru catalysts with chiral biaryl ligands such as C3-TunaPhos, and up to over 99% ee's have been achieved. This methodology provides an efficient catalytic method for the synthesis of both cis and trans chiral cyclic beta-amino acid derivatives.     

Practical Rh(I)-catalyzed asymmetric hydrogenation of beta-(acylamino)acrylates using a new unsymmetrical hybrid ferrocenylphosphine-phosphoramidite ligand: crucial influence of an N-H proton in the ligand

[reaction: see text] Excellent enantioselectivities and high turnovers (S/C = 5000) were achieved in the Rh(I)-catalyzed asymmetric hydrogenation of both beta-aryl- and beta-alkyl-beta-(acylamino)acrylates with a new unsymmetrical hybrid ferrocenylphosphine-phosphoramidite ligand, and the presence of an N-H proton in the ligand was demonstrated to have a crucial role in the enantioselectivity.     

Synthesis, Crystal Structure and Hydrogenation Catalysis of a CF3-BINAP（O）-Rh-COD Complex

The complex [(CF3-BINAP(O))Rh(COD)][ClO4]·Et2O(2,CF3-BINAP(O)=2-{bis[3,5-bis(trifluoromethyl)phenyl]phosphino}-2-{bis[3,5-bis(trifluoromethyl)phenyl]phosphinyl}-1,1-binaphthyl, COD=1,5-cyclooctadiene) was obtained directly from the reaction of CF 3-BINAP(O) ligand with [Rh(COD)][ClO4]. Complex 2 has been characterized by single-crystal X-ray diffraction. The crystal adopts space group P21/n with a=19.0727(4), b=15.6275(4), c=22.3039(6), β=112.3570(10)°, V=6148.2(3)3 , Z=4, Dc=1.693 g/cm3 , F(000)=3144, μ(MoKα)=0.500 mm-1 , the final R=0.0947 and wR=0.2501. Structural studies reveal that Rh(I) is coordinated by one oxygen and one phosphorus in the same ligand. Asymmetric hydrogenation of acetami- docinnamic acid with compound 2 was also evaluated.