Palladium-catalyzed regiocontrolled and stereoselective alkylations of bis(trifluoroethyl) malonates with dienyl alcohols

The triethylborane-promoted and palladium-catalyzed reactions of 2,4-dienyl alcohols or the corresponding isomeric divinyl alcohols with bis(trifluoroethyl) malonates provide an improved method for the regio- and stereoselective dienylation of malonates. The phosphine ligand is an important control element in the reaction. Combinations of Pd(OAc)₂ with BIPHEP or BINAP give dienylated malonates in good yield and higher isomeric purity than the traditional combination of Pd(OAc)₂ and Ph₃P affords in the catalyzed reactions of dienyl acetates.     

Synthesis of β‐Arylacyl/β‐Heteroarylacyl‐β‐alkylidene Malonates and Their Application in Substituted Pyridone Synthesis

A novel approach has been developed for the synthesis of β‐arylacyl/β‐heteroarylacyl‐β‐alkylidine malonates in moderate to good yields by the reaction of Stork aryl and heteroaryl enamine with β‐chloroalkylidene malonates. The reaction involves conjugate (Michael) addition of Stork enamine on β‐chloroalkylidene malonates and elimination of chloride ion. These Michael adducts were utilized as intermediates for the synthesis of highly substituted 1,4‐dialkyl‐2‐oxo‐6‐aryl/hetreoaryl‐1,2‐dihydro‐pyridine‐3‐carboxylic acid ethyl esters via 5 + 1 ring annulation protocol.     

Retrocyclopropanation reactions of fullerenes: complete product analyses

Mono- and bis-pyrene malonates 1 and 2 were synthesized and reacted with C(60) to prepare the corresponding Bingel adducts 3 and 4. These compounds were characterized electrochemically and exhibited the well-established retrocyclopropanation reaction when subjected to bulk electrolytic reductions. For the first time, it was possible to perform detailed product analyses after the retrocyclopropanation reactions, and these showed the presence of the original malonates 1 and 2 along with C(60), in reasonable yields, around 50%.     

Synthesis and reactions of tetrazolo[1,5-α]pyrimidines

The reaction of “magic malonates” (bis-2,4,6-trichlorophenyl malonates, 1 ) with 5-aminotetrazole ( 2 ) in the presence of triethylamine yields the ammonium salts 3 . Upon treatment of 3 with strong acids compounds 4a-d were obtained as a mixture of isomeric tetrazolopyrimidines ( A ) and 2-azidopyrimidines ( B ). Reaction of 4d with bromine or sulfuryl chloride leads by ring opening and decarboxylation to the halogenated tetrazole derivatives 5 or 7 , respectively. The action of acetic anhydride in pyridine on 3d yields the zwitterionic tetra-mic acid derivative 10.     

Reactions of 2-Phosphonylethynylated 2-(Arylamino)malonates with Some Bases

Russian Journal of General Chemistry - The reaction of dialkyl 2-[(dialkoxyphosphoryl)ethynyl]-2-(arylamino)malonates with bases (CH3COOK, t-BuOK) can serve as a method for preparing original...     

Synthesis of highly symmetric mesomeric triazaphenalene betaines

The synthesis of seven mesomeric triazaphenalene betaines 4a‐g by condensation reaction of hexahydro‐2H‐pyrimido[1,2‐a]pyrimidine 1 with diethyl malonates 2a‐g or with bis(2,4,6‐trichlorophenyl)malonates 3c,f has been achieved. The guanidine 1 forms in benzene solution a salt with trimethyl methanetricarboxylate 5 which upon heating produces 4a.     

Polybromoaromatic Compounds: IX. Reactions of Polybromobenzyl Bromides with Enolates Derived from Some Dicarbonyl Compounds

The reaction of polybromobenzyl bromides RC₆Br₄CH₂Br (R = Br, OCH₃) with diethyl malonate sodium salt in ethanol and dimethylformamide leads to formation of diethyl 2-(polybromobenzyl)malonates, whereas in aqueous ethanol ethyl polybromobenzyl malonates are formed. The same polybromobenzyl bromides react with an equimolar amount of ethyl acetoacetate sodium salt or acetylacetone sodium salt to give C-alkylation products; with excess sodium enolates ethyl 3-(polybromophenyl)propionates and 4-(polybromophenyl)-2-butanones are formed, respectively.     

Synthesis and reactions of 4-Hydroxy-2(1H)-pyridones with thienyl and pyridyl substituents in position 6 starting with azomethines and malonates

The reaction of 4 with substituted diethyl malonates 5a , or “magic malonates” (bis-2,4,6-trichlorophenylmalonates 5b ) leads to 4-hydroxy-2(1H)-pyridones 6. The azomethines 4 are prepared via the Strecker compounds 3 starting with methyl ketones 1 , anilines, and potassium cyanide. Chlorination of pyridones 6 with sulfuryl chloride leads to compounds 7 while nitration gives 9.     

Synthesis of 2-substituted 3-aroylindenes via palladium-catalyzed carbonylative cyclization of diethyl 2-(2-(1-alkynyl)phenyl)malonates with aryl halides

[reaction: see text] The palladium-catalyzed reaction of readily accessible diethyl 2-(2-(1-alkynyl)phenyl)malonates with aryl halides under a balloon pressure of CO produced 2-substitued 3-aroylindenes in good yields. The reaction is believed to proceed via cyclization of the alkyne containing a proximate nucleophilic center promoted by an acylpalladium complex.     

Reverse of regioselectivity in intramolecular nucleophilic substitution of pi-allyl palladium species. Highly selective formation of vinylic cyclopropanes via the Pd(0)-catalyzed coupling-cyclization reaction of organic iodides with 2-(2', 3'-Dienyl)malonates

Vinylic cyclopropanes were formed highly selectively via the Pd(PPh(3))(4)-catalyzed insertion-intramolecular nucleophilic substitution reaction of aryl or 1-alkenyl iodides with 2-(2', 3'-dienyl)malonates. The regioselectivity observed here is different from what was reported by Cazes et al.     

Fe-Catalyzed reactions of 2-chloro-1,7-dienes and allylmalonates

Fe(III)(BIAP)Cl₃ complex catalyzes alkylative cyclization of 2-chloro-1,7-heptadiene in the presence of triethylaluminum. It also catalyzes deallylation of certain 2-allyl-2-substituted malonates under the same reaction conditions.     

3-取代-(1H)-嘧啶[1, 2-a]喹啉-1-酮和2-取代嘧啶[1, 2a]苯骈 咪唑-4-(10H)- 酮的简便合成法

本文利用2-氨基喹啉和2-氨基苯骈咪唑作为亲核试剂,与5-(双甲硫基亚甲基)丙二酸亚异丙酯(1)、5-(甲硫基亚烃基)丙二酸亚异丙酯(3)反应,开发出3-取代-(1H)-嘧啶-[1,2-a]喹啉-1-酮(5)和2-取代嘧啶[1,2-a]苯骈咪唑-4-(10H)-酮(6)通用的简便合成法。     

Efficient palladium-catalyzed cross-coupling of beta-chloroalkylidene/arylidene malonates using microwave chemistry

A general method for the synthesis of beta-aryl/alkylarylidene malonates is reported. The key step involves the coupling of an arylboronic acid to a beta-chloroalkyl/arylidene malonate, in the presence of K2CO3 and 1 mol % of the air-stable palladium catalyst (POPd) under microwave irradiation, to afford beta-aryl/alkylarylidene malonates in good yields. The combination of mild reaction conditions, air stable catalyst, microwave-enhanced chemistry, and high levels of functional group compatibility make this an attractive synthetic approach to this class of compounds.     

苯基(苯乙炔基)对甲苯磺酸碘(Ⅲ)的应用──5-烃基-5-苯乙炔基丙二酸亚异丙酯的合成

近年来，随着元素周期表中第VA，VIA族元素有机化合物在合成中得到了广泛的应用，激起人们对有机高价碘化物在合成中应用的兴趣［’－‘j．苯基（快基）碘盐（1）是具有多个亲电中心的化合物，在不同亲核试剂的作用下，分子中有3个部位可受到进攻［‘”j．由于通常的炔基卤化物对许多条核试剂的反应比较惰性，或者产物较为复杂，在合成上的应用受到限制．而化合物1作为快基的阳离子等效体的反应在会成上则很有价值＊，。‘．5一烃基丙二酸亚异丙酯在有机合成中是具有多种反应性能的试剂，同时又是许多热解反应的有效前体．至今，有关5一取…     

Manganese (III) Acetate Initiated Oxidative Free Radical Reaction of 3-Heteroaryl Substituted Malonates

The manganese (III) initiated oxidative free radical reaction of electron rich 3-heteroaryl substituted malonates is described.     

Rearrangement reactions of heterocycles. 12. Rearrangement of 6-substituted pyrido[1,2-a]pyrimidines to isomeric 1,8-naphthyridines and some of their further reactions

2-Amino-6-methylpyridine ( 4 ) reacts with active malonates 2a-d or 3a-d either in acetone solution with triethylamine as catalyst at room temperature or with active malonates 2a-d in acetone solution at reflux temperature to yield the pyrido[1,2-a]pyrimidines 5a-d . 2,6-Diaminopyridine ( 8 ) already reacts without triethylamine with 2a-d at room temperature to afford the pyrido[1,2-a]pyrimidines 9a-d . At higher temperatures pyrido[1,2-a]pyrimidines 5 and 9 are rearranged via ketene intermediates [1] to yield the 1,8-naphthyridines 6a-d , and 10a-d , respectively. The naphthyridines 6 and 10 can also be synthesized directly from 4 or 8 using either diethyl malonates 1 or — with better results — the active malonates 2 at 240–250°. Further reaction of 10a-e with 2c,d leads to the pyridonaphthyridines 12a-f . Nitration of 6c yields the nitro derivative 16 and chlorination of 6c,d gives 15c,d , while the chlorination of 10c affords the di-chloro derivative 17 .     

Catalytic asymmetric ring-opening of meso-aziridines with malonates under heterodinuclear rare earth metal Schiff base catalysis

Catalytic asymmetric ring-opening of meso-aziridines with malonates is described. The combined use of two rare earth metal sources with different properties promoted the desired ring-opening reaction. A 1:1:1 mixture of a heterobimetallic La(O-iPr)(3)/Yb(OTf)(3)/Schiff base 1a (0.25-10 mol %) efficiently promoted the reaction of five-, six-, and seven-membered ring cyclic meso-aziridines as well as acyclic meso-aziridines with dimethyl, diethyl, and dibenzyl malonates, giving chiral cyclic and acyclic γ-amino esters in 99-63% yield and >99.5-97% ee.     

Reaction of 2-[Aryl(alkyl)amino]malonates with Chloroethynylphosphonates

Russian Journal of General Chemistry - Preparative limitations of the reaction of chloroethynylphosphonates with 2-(alkylamino)malonates have been established. Unlike the reaction of...     

Highly regio- and stereoselective synthesis of polysubstituted cyclopropane compounds via the Pd(0)-catalyzed coupling-cyclization reaction of 2-(2',3'-allenyl)malonates with organic halides

A new method for highly regio- and stereoselective synthesis of polysubstituted cyclopropane compounds via the Pd(0)-catalyzed coupling-cyclization reaction of 2-(2',3'-allenyl)malonates with organic halides is described. In these reactions, the starting materials are easily available and the operation is convenient. The ratios of trans-isomer/cis-vinylic cyclopropanes are up to 98:2.     

导向有机合成的金属有机化学研究初探

总结了麻生明自1997年回国后在国家自然科学基金委、科技部、中国科学院、上海市科委的共同资助下开展的一些研究工作：(1)联烯化学;(2)偶联反应的区域选择性研究-1-芳基-1-炔烃的单锂化反应;(3)多中心反应-1,1-二溴-1-烯烃的氧化加成反应,α-脱卤钯化反应和分子内双环钯碳化反应。