Baylis-Hillman反应的研究进展

介绍子一种形成碳碳键的方法－Baylis-Hillman反应及其研究的最新进展。为克服常见Baylis-Hillman反应反应速度慢的缺点,近来人们发展了许多加快反应速度的方法。运用手性底物或手性催化剂等方法来进行不对称Baylis-Hillman反应从而获得手性Baylis-Hillman加成产物。     

'Double asymmetric induction' as a novel tool for high stereocontrol in Baylis-Hillman reaction

The strategy of double asymmetric induction was utilized in Baylis-Hillman reaction for the first time by the coupling of chiral aldehydes with chiral acrylate (1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose-3-acrylate) to obtain corresponding adducts with high syn diastereoselectivities (de >90%) in moderate to good yields.     

(-)-8-Phenylmenthyl Acrylate as Chiral Inducer in the Baylis-Hillman Reaction

8-Phenylmenthol 1 is used as a chiral auxiliary in the Baylis-Hillman reaction using a range of aldehydes as substrate. Best results (70% d. e.) are obtained when the reaction is rapid, as is the case with trichloroacetaldehyde.     

First application of chiral ionic liquids in asymmetric Baylis-Hillman reaction

The first example of the use of chiral ionic liquids as reaction media in the asymmetric Baylis-Hillman reaction was described using N-alkyl-N-methylephedrinium salts. Good yields and significant enantiomeric excesses were obtained.     

Chiral Lewis acid-catalyzed asymmetric Baylis-Hillman reactions

An effective chiral Lewis acid-catalyzed asymmetric Baylis-Hillman reaction is described. Good to high enantioselectivities were obtained using 3 mol % chiral catalyst. Novel camphor-derived dimerized ligands were prepared from the condensation of (+)-ketopinic acid with the corresponding diamines and hydrazine under acidic conditions. When alpha-naphthyl acrylate was used as a Michael acceptor, the reaction is complete within 20 min with high stereoselectivity and in reasonable chemical yields.     

Novel functionalized trisubstituted allylboronates via Hosomi-Miyaura borylation of functionalized allyl acetates

[reaction: see text] A series of novel functionalized achiral and chiral allylboronates have been synthesized via the nucleophilic addition of boronates on allyl acetates derived via vinylalumination or Baylis-Hillman reaction of aldehydes. These reagents, upon allylboration with aldehydes, furnish beta-substituted-alpha-methylene-gamma-butyrolactones stereoselectively.     

"Diversity oriented synthesis" of functionalized chiral tetrahydropyridines: potential GABA receptor agonists and azasugars from natural amino acids via a sequential Baylis-Hillman reaction and RCM protocol

The preparation of chiral tetrahydropyridine-4-carboxylates as isoguvacine analogues and azasugars with a tertiary stereocenter from L-amino acids via diastereoselective a Baylis-Hillman reaction of N-allyl-Boc alpha-aminal, followed by ring-closing metathesis and dihydroxylation sequences, is reported.     

First diastereoselective intramolecular Baylis-Hillman reaction: an easy access to chiral alpha-methylene-beta-hydroxylactones

The first diastereoselective intramolecular Baylis-Hillman reaction of chiral substrates is reported wherein both aldehyde and activated olefin coexist as substituents to afford alpha-methylene-beta-hydroxylactones in good yields exclusively as single isomers under the standard base-catalyzed reaction conditions in CH(2)Cl(2). Formation of alkoxylactones by an in situ derivatization of adducts was also observed.     

聚乙二醇(400)中的不对称Baylis-Hillman反应

从易得的L-脯氨酸出发, 方便地合成了氨基醇1. 以聚乙二醇(400)为溶剂, 考察了手性氨基醇1 (30 mol%)在聚乙二醇(400)中催化不对称的Baylis-Hillman反应, 有较好的催化活性和立体选择性, 产率最高达95.4%, ee值最高达54.3%. 手性氨基醇1-聚乙二醇(400)催化体系可方便回收并重复利用, 在前三次循环中, 未发现反应产率和选择性有明显变化.     

脯氨酸催化的不对称有机反应

脯氨酸作为一种结构简单、商品化的、廉价小分子手性催化剂,在多种不对称催化反应中表现出非常好的催化性能,本文综述了近年来脯氨酸直接催化的不对称有机反应涉及Aldol反应,Mannich反应,Michael反应,Diels-Alder反应,直接α-胺化反应,α-氧胺化反应,Baylis-Hillman反应,还原反应和氧化反应的进展并展望了其应用前景。     

Development of bis-thiourea-type organocatalyst for asymmetric Baylis-Hillman reaction

A new chiral bis-thiourea-type organocatalyst 2 developed for the Baylis-Hillman reaction provided a drastic rate enhancement. Allylic alcohols were obtained with up to 90% ee in the case of cyclohexanecarboxaldehyde (4i).     

Chiral phosphinothiourea-catalyzed asymmetric Morita-Baylis-Hillman reactions of acrylates with aromatic aldehydes

A series of chiral bifunctional phosphinothioureas were synthesized and applied to the enantioselective Morita-Baylis-Hillman reaction of aromatic aldehydes with acrylates. In the presence of 8 mol % of organocatalyst 2e, the Baylis-Hillman adducts were obtained in good enantioselectivities and up to 96% yield under mild reaction conditions.     

Design and synthesis of bistereogenic chiral ionic liquids and their use as solvents for asymmetric Baylis-Hillman reactions

Three novel chiral ionic liquids (CILs) containing two chiral centers in the side chain bonded to the 2-position of the imidazolium cation and different anions have been synthesized, characterized and used as chiral solvents for asymmetric Baylis-Hillman (BH) reactions; good yields and fair enantioselectivities were obtained.     

胺催化下的Baylis-Hillman反应

Baylis-Hillman (B-H)反应是在催化剂作用下由活泼烯烃和亲电试剂发生的偶合反应, 其产物是一个具有多官能团的化合物. 胺类催化剂是反应中应用最广泛的一类催化剂. 综述了各种胺催化下的Baylis-Hillman反应的研究进展.     

Beta-isocupreidine-catalyzed Baylis-Hillman reaction of chiral N-boc-alpha-amino aldehydes

[Structure: see text] Beta-isocupreidine (beta-ICD)-catalyzed Baylis-Hillman reaction of chiral N-Boc-alpha-amino aldehydes and 1,1,1,3,3,3-hexafluoroisopropyl acrylate (HFIPA) takes place without racemization and exhibits the match-mismatch relationship between the substrate and the catalyst. In the case of acyclic amino aldehydes, L-substrates show excellent syn selectivity and high reactivity in contrast to D-substrates. On the other hand, in the case of cyclic amino aldehydes, D-substrates rather than L-substrates show excellent anti selectivity and high reactivity.     

Lewis base effects in the Baylis-Hillman reaction of imines with cyclohex-2-en-1-one and cyclopent-2-en-1-one

In the Baylis-Hillman reaction of N-benzylidene-4-methyl-benzenesulfonamide with cyclohex-2-en-1-one or cyclopent-2-en-1-one, we found that, in the presence of a catalytic amount of DMAP, the Baylis-Hillman reaction can be greatly accelerated to give the normal Baylis-Hillman adduct 1 or 3 in good or very high yields: moreover, using PBu3 as a Lewis base in the reaction of N-benzylidene-4-methylbenzenesulfonamide with cyclopent-2-en-1-one, the normal Baylis-Hillman adducts 3 could be obtained in very high yields within 5 h, however, using PBu3 or DBU as a Lewis base in the reaction of N-benzylidene-4-methyl-benzenesulfonamide with cyclohex-2-en-1-one, beside the normal Baylis-Hillman adduct 1 abnormal Baylis-Hillman adduct 3-aryl-2-[(4-methylphenyl)sulfonyl]-2-azabicyclo[2.2.2]octan-5-one 2 was formed at the same time; the substituent's effects were also examined.     

Baylis-Hillman Reaction Involving Substituted Cyclic Enones in Aqueous Media

β-Substituted enones have been considered less reactive in Baylis-Hillman reaction. The reaction of cyclicenones is sluggish or does not occur at all under traditional conditions. [1] Therefore, substituted cyclic enones havebeen less explored in Baylis-Hillman reaction due to the extremely low reactivity. In this communication, we reported Baylis-Hillman reaction of substituted cyclic enones using our previously developed conditions with imidazole as catalyst. The reaction proceeded smoothly in aqueous media affording the desired product with good yields and moderate diastereoselectivity.     

An asymmetric nickel-chromium coupling toward the synthesis of Baylis-Hillman adducts

An asymmetric nickel-chromium coupling strategy has been employed in the generation of enantioenriched Baylis-Hillman adducts with selectivities reaching >90% ee and in fair to moderate yields (up to 65%) using a chiral sulfonamide ligand. The reaction conditions appear to show reasonable generality and are compatible with both aromatic and aliphatic aldehydes. Utilizing such a strategy not only allows for the preparation of products which contain substitution at the β-position on the olefin but also allows for the separation of olefin isomers in this transformation.     

A novel modified baylis-hillman reaction of propiolate

A new reaction of propiolates and aldehydes mediated by DABCO analogous to the Baylis-Hillman reaction is described. This reaction provided novel beta-functionalized Baylis-Hillman products and a new methodology for the generation of alkylidene carbene species.     

Azoles: Effective Catalysts for Baylis-Hillman Reaction in Aqueous Media

β-Substituted enones have been considered less reactive in Baylis-Hillman reaction. The reaction of cyclic enones is sluggish or does not occur at all under traditional conditions. Various catalysts have been developed to pro mote the reaction of cyclic enones but with limited success. In previous study, we found that imidazole can catalyze the Baylis-Hillman reaction involving cyclic enones in aqueous THF solution. [1] In our continued efforts, a variety of azole compounds were examined in Baylis-Hillman reaction. We found that the azoles act as effective catalysts in properly adjusted water solution.