Efficient synthesis of 5,6-dihydrothieno[3′,2′:4,5]-thieno[2,3-d]pyrimidin-4(3H)-ones via an iminophosphorane

5,6-Dihydrothieno[3＇,2＇：4,5]thieno[2,3-d]pyrimidin-4（3H）-ones 6 were synthesized in yields of 71-87% by a consecutive method, which includes aza-Wittig reaction of iminophosphorane 3 with aromatic isocynate to give carbodiimide 4 and subsequent reaction of 4 with various amines, phenols or alcohols in the presence of catalytic amount of sodium ethoxide or solid potassium carbonate. 2009 Ming Wu Ding. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

New efficient synthesis of 2,5,6-trisubstituted oxazolo[5,4-d]pyrimidi-7(6H)-ones via an oxazolyliminophosphorane

A new efficient synthesis of 2,5,6-trisubstituted oxazolo（5,4-d]pyrimidi-7（6H）-ones by consecutive azaWittig reaction was developed.The sequential three-component reaction of oxazolyliminophosphorane4,isocyanates and amines produced 2,5,6-trisubstituted oxazolo[5,4-d]pyrimidi-7（6H）-ones 7 in good overall yields in the presence of catalytic amount of EtONa.

Chiral iminophosphorane catalyzed asymmetric Henry reaction of α,β-alkynyl ketoesters

α,β-Alkynyl ketoesters were introduced to the enantioselective Henry reaction(nitroaldol condensation)with nitromethane catalyzed by tartaric acid derived chiral iminophosphoranes.As such,a variety of optically activeβ-nitro-substituted tertiary alcohols bearing alkyne moieties were obtained in good to excellent yields(42%–99%)and moderate to good level of enantiomeric excess(up to 87%ee).

New Facile Synthesis of 2-Aryloxy-5-(2-furfurylidene)- 4H-imidazolin-4-ones

Novel 2-aryloxy-5-(2-furfurylidene)-4H-imidazolin-4-ones 6 were synthesized by aza-Wittig reaction of vinyliminophosphorane 4 with phenyl isocyanate and subsequent condensation with Various substituted phenols in the presence of catalytic amount of potassium carbonate. The products are confirmed by H-1 NMR, MS, IR and elementary analysis.

A Rapid Parallel Synthesis of 2-Dialkylamino-4(3H)-quinazolines

Dialkylamino-4(3H)-quinazolinones 4 were rapidly synthesized by a solution-phase parallel synthetic method, which includes aza-Wittig reaction of iminophosphorane 1 with aromatic isocynate to give carbodiimide 2 and subsequent reaction of 2 with various aliphatic secondary amine in a parallel fashion.

Efficient synthesis of 4(3H)-quinazolinones using a soluble polymeric support

4（3H）-Quinazolinones have been synthesized from poly（ethylene glycol） （PEG） supported aza-Wittig reaction. 2-Dialkylamino- 4（3H）-quinazolinones 6 were synthesized efficiently by reaction of secondary amine with PEG-supported carbodiimides 4, which were obtained from aza-Wittig reaction of PEG-supported iminophosphoranes 3 with isocyanates.

A Selective Synthesis of 2-Alkylamino-5, 6, 7, 8-tetrahydro-benzothieno[2, 3-d]pyrimidin-4(3H)-ones

Alkylamino-5, 6, 7, 8-tetrahydrobenzothieno [2, 3-d] pyrimidin-4(3H)-ones 7 weresynthesized by a new selective synthetic method, which includes aza-Wittig reaction of imino-phosphorane 4 with aromatic isocynate to give carbodiimide 5 and subsequent reaction of 5 withvarious aliphatic primary amine in the presence of EtO-Na+.

Synthesis and Crystal Structure of 2-(4’-Methylphenoxy)-5,8,9-trimethyl-3-phenyl Thieno[3′,2′:5,6]pyrido[4,3-d]pyrimidin-4-(3H)-one Hydrochloride

The title compound 2-（4＇-methylphenoxy）-5,8,9-trimethyl-3-phenyl thieno[3＇,2＇：5,6] pyrido[4,3-d]pyrimidin-4（3H）-one hydrochloride （C26H23Cl4N3O2S, Mr = 583.33） has been determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a = 14.8442（ 11 ）, b = 11.5131 （8）, c = 17.2010（13） A, β = 113.7250（10）°, V = 2691.3（3） ,A^3, Z = 4, Dc = 1.440 g/cm^3, S = 1.094,μ = 0.547 mm^-1, F（000） = 1200, the final R = 0.0571 and wR = 0.1458. X-ray analysis reveals that the title compound combines with a molecule of dichloromethane by an intramolecular hydrogen bond. The thienopyridine ring is almost coplanar, and the dihedral angle between the thiophene plane and the pyridine plane is 0.6°.

Novel Tandem Three Consecutive Reactions: Aza-Wittig, Imine Condensation and Electrophilic Aromatic Substitution Strategy to Indolizine Synthesis

Reaction of ethyl (Z)-3-(heteroaryl/aryl)-2-((triphenyl-λ5-phosphaneylidene) amino) acrylates intermediates with 2,3-thiophenedicarboxaldehyde was used in novel Tandem three consecutive reactions: aza-Wittig, imine condensation and electrophilic heteroaromatic cyclization to obtain a series of indolizines. A tentative mechanism of this reaction is proposed.

An efficient route for synthesis of 2-alkylamino benzo[b]thieno[3,2-d]pyrimidin-4(3H)-one

The carbodiimide 2,obtained from the aza-Wittig reactions of iminophosphorane 1 with alkyl isocyanates,reacted with primary amino to give 2-alkylamino benzo[b]thieno[3,2-d]pyrimidin-4（3H）-ones 4 and 5.The formation mechanism of the title compounds has been investigated.

Chiral organobases: Properties and applications in asymmetric catalysis

Chiral organobases occupy a significant position in asymmetric organocatalysis. The general types of chiral organobases include tertiary amines, amidines, guanidines, cyclopropenimines, and iminophosphoranes, etc. These organobases are demonstrated to be effective organocatalysts to promote divers kinds of base-initiated reactions in excellent yields and stereoselectivities. In previous reports, several groups have summarized each kind of chiral organobases in different reviews. To the aim of understanding the whole of them in one review, herein, we provide a brief introduction of these chiral organobases in asymmetric catalysis.

Facile Synthesis of Phosphorus N-Fluoroalkanesulfonyl Amidines by Cu-catalyzed One-pot Three-component Reaction

In the presence of Cu（I） and triethyl amine, one-pot three-component reaction of fluoroalkanesulfonyl azides, alkynes and iminophosphoranes in CH2Cl2 at room temperature gave a novel class of fluorinated phosphorus amidines in good yields.

Efficient Regioselective Synthesis of 3-1odoindole N-Carboximidamides and N-Carboximidoates by a Sequential Aza-Wittig/Iodine Induced Cyclization

3-Iodoindole N-carboximidamides and N-carboximidoates 4 were prepared regioselectively via a sequential aza-Wittig/iodine induced cyclization, starting from easily accessible 2-alkynylphenyl iminophosphorane, isocyanates, various nucleophiles and iodine.