Value-added oil and animal feed production from corn-ethanol stillage using the oleaginous fungus Mucor circinelloides.

This study highlights the potential of oleaginous fungus, Mucor circinelloides in adsorbing/assimilating oil and nutrients in thin stillage (TS), and producing lipid and protein-rich fungal biomass. Fungal cultivation on TS for 2 days in a 6-L airlift bioreactor, resulted in a 92% increase in oil yield from TS, and 20 g/L of fungal biomass (dry) with a lipid content of 46% (g of oil per 100g dry biomass). Reduction in suspended solids and soluble chemical oxygen demand (SCOD) in TS were 95% and 89%, respectively.

Tetrabutylammonium fluoride (TBAF)-catalyzed addition of substituted trialkylsilylalkynes to aldehydes, ketones, and trifluoromethyl ketones.

Herein we report that tetrabutylammonium fluoride (TBAF) is a very efficient catalyst for the addition of trialkylsilylalkynes to aldehydes, ketones, and trifluoromethyl ketones in THF solvent at room temperature. The reaction conditions are mild and operationally simple, and a variety of aryl functional groups, such as chloro, trifluoromethyl, bromo, and fluoro groups, are tolerated. Impressively, using our protocol, useful CF(3)-bearing tertiary propargylic alcohols can be synthesized.

P[N(i-Bu)CH(2)CH(2)](3)N: nonionic Lewis base for promoting the room-temperature synthesis of α,β-unsaturated esters, fluorides, ketones, and nitriles using Wadsworth-Emmons phosphonates.

The bicyclic triaminophosphine P(RNCH(2)CH(2))(3)N (R = i-Bu, 1c) serves as an effective promoter for the room-temperature stereoselective synthesis of α,β-unsaturated esters, fluorides, and nitriles from a wide array of aromatic, aliphatic, heterocyclic, and cyclic aldehydes and ketones, using a range of Wadsworth-Emmons (WE) phosphonates. Among the analogues of 1c [R = Me (1a), i-Pr (1b), Bn (1d)], 1a and 1b performed well, although longer reaction times were involved, and 1d led to poorer yields than 1c. Functionalities such as cyano, chloro, bromo, methoxy, amino, ester, and nitro were well tolerated.

An electron-rich proazaphosphatrane for isocyanate trimerization to isocyanurates.

A facile synthesis of the new electron-rich, sterically hindered proazaphosphatrane shown above is described herein. This proazaphosphatrane catalyzes the cyclotrimerization of a wide variety of isocyanates to isocyanurates under mild conditions with unprecedentedly fast reaction times, giving moderate to high product yields. It is also shown that this proazaphosphatrane can be recycled up to 5 times.

Advantageous use of tBu2P-N=P(iBuNCH2CH2)3N in the Hiyama coupling of aryl bromides and chlorides.

An efficient catalytic route to biaryls by employing (generally) only 0.25 mol % of Pd(OAc)(2) and 0.5 mol % of 1 in the Hiyama coupling reaction is reported.

P(PhCH2NCH2CH2)3N catalysis of Mukaiyama aldol reactions of aliphatic, aromatic, and heterocyclic aldehydes and trifluoromethyl phenyl ketone.

Herein we find that proazaphosphatrane 1c is a very efficient catalyst for Mukaiyama aldol reactions of aldehydes with trimethylsilyl enolates in THF solvent. Only the activated ketone 2,2,2-trifluoroacetophenone underwent clean aldol product formation with a variety of trimethylsilyl enolates under similar conditions as the aldehydes. The reactions were carried out at room temperature using (1-methoxy-2-methyl-1-propenyloxy)trimethylsilane, whereas the temperature was -15 degrees C in the case of 1-phenyl-1-(trimethylsilyloxy)ethylene.

P(PhCH(2)NCH(2)CH(2))(3)N: an efficient lewis base catalyst for the synthesis of propargylic alcohols and Morita-Baylis-Hillman adducts via aldehyde alkynylation.

Proazaphosphatrane P(PhCH(2)NCH(2)CH(2))(3)N (1a) is an efficient catalyst for the addition of aryl trimethylsilyl alkynes to a variety of aromatic, aliphatic, and heterocyclic aldehydes in THF at room temperature. The reaction conditions are mild and employ a low catalyst loading (ca. 5 mol %).

P(i-PrNCH2CH2)3N as a Lewis base catalyst for the synthesis of beta-hydroxynitriles using TMSAN.

Proazaphosphatrane 1a was found to be an efficient catalyst for synthesis of beta-hydroxynitriles via the reaction of trimethylsilylacetonitrile (TMSAN) with aldehydes under mild reaction conditions and typically low catalyst loading (ca. 2 mol %). A variety of functional groups were tolerated, and good to excellent product yields were obtained.

Catalysis of mukaiyama aldol reactions by a tricyclic aluminum alkoxide Lewis acid.

The Mukayiama aldol reaction of aldehydes is efficiently accomplished with a low concentration of the dimeric alumatrane catalyst 2 at mild or subambient temperatures. Our protocol tolerates a wide variety of electron-rich, neutral, and deficient aryl, alkyl, and heterocyclic aldehydes. A wide variety of enol silyl ethers are also tolerated.

P(i-PrNCH2CH2)3N: efficient catalyst for synthesizing beta-hydroxyesters and alpha,beta-unsaturated esters using alpha-trimethylsilylethylacetate (TMSEA).

We present an efficient synthesis of beta-hydroxyesters and alpha,beta-unsaturated esters via activation of the silicon-carbon bond of alpha-trimethylsilylethylacetate using catalytic amounts of the commercially available P(i-PrNCH(2)CH(2))(3)N 1a. Selectivity for either of these two products can be achieved simply by altering the catalyst loading and reaction temperature to afford addition or stereoselective condensation. This method is mild and tolerates a wide array of functional groups.

Cellulose conversion in dry grind ethanol plants.

The expansion of the dry grind ethanol industry provides a unique opportunity to introduce cellulose conversion technology to existing grain to ethanol plants, while enhancing ethanol yields by up to 14%, and decreasing the volume while increasing protein content of distiller's grains. The technologies required are cellulose pretreatment, enzyme hydrolysis, fermentation, and drying. Laboratory data combined with compositional analysis and process simulations are used to present a comparative analysis of a dry grind process to a process with pretreatment and hydrolysis of cellulose in distiller's grains.

(t-Bu)2PN=P(i-BuNCH2CH2)3N: new efficient ligand for palladium-catalyzed C-N couplings of aryl and heteroaryl bromides and chlorides and for vinyl bromides at room temperature.

By employing Pd(OAc)2, Cs2CO3, or NaOH, and the new ligand (t-Bu)2PN=P(i-BuNCH2CH2)3N (3a), an electronically diverse array of aryl bromides and chlorides possessing base-sensitive substituents (nitro, ester, and keto) provide coupling products with bulky aryl amines in good to excellent yields. Aryl halides possessing other functional groups including cyano, amino, trifluoromethyl, and phenol, coupled with equal ease, producing highly functionalized amines in good to excellent yields. Moreover, an aryl chloro group can be preserved in the presence of a bromo substituent under our reaction conditions.

Water solubilization of DDGS via derivatization with phosphite esters.

Ethanol production from corn starch in the corn dry milling process leaves Distillers' Dry Grains and Solubles (DDGS) as a major by-product from which additional ethanol may be economically obtained from its glucan content. A challenge in processing the cellulose content of this material lies in its extensive inter-cellulose chain hydrogen bonding, which inhibits access of enzymes capable of cleaving glycosidic bonds, a transformation required for providing fermentable sugars. The phosphitylation of cellulosic OH groups using a reactive bicyclic phosphite ester is utilized to disrupt cellulosic hydrogen bonds, thus providing access to cellulose chains for further processing.

Comparisons of phosphorus ligation properties in P(CH2NR)3P.

Bicyclic P(CH2NMe)3P was synthesized, and its reactions with MnO2, elemental sulfur, p-toluenesulfonyl azide, BH3.THF, and W(CO)5(THF) were shown to furnish a variety of products in which the PC3 and/or the PN3 phosphorus are oxidized/coordinated. In contrast, reactions of the previously known P(CH2NPh)3P with Mo(0) and Ru(II) precursors were shown to afford products in which only the PC3 phosphorus is coordinated.

Steric stabilization of a monomeric proalumatrane: experimental and theoretical studies.

Treatment of tripodal tris(3-tert-butyl-2-hydroxy-5-methylbenzyl)amine (L) with 1 equiv of trimethylaluminum in toluene gave the stable proalumatrane (AlL) (1) [wherein L = tris(3-tert-butyl-5-methyl-2-oxidobenzyl)amine] featuring a distorted trigonal monopyramidal four-coordinate aluminum geometry. An analogous reaction uses the less sterically congested isomer of L, namely, tris(5-tert-butyl-2-hydroxy-3-methylbenzyl)amine provided dimeric (AlL')2 (2) [wherein L' = tris(5-tert-butyl-3-methyl-2-oxidobenzyl)amine], which contains two bridging alumatrane moieties possessing five-coordinate TBP aluminum geometries. Reaction of AlL with water provided the adduct H2O.

Synthesis and characterization of R2PN=P(iBuNCH2CH2)3N: a new bulky electron-rich phosphine for efficient Pd-assisted Suzuki-Miyaura cross-coupling reactions.

Pro-azaphosphatrane 1a [P(iBuNCH2CH2)3N] reacts with iodine under mild conditions to give [IP(iBuNCH2CH2)3N]I in excellent yield, which on subsequent reaction with ammonia followed by deprotonation with KOtBu provided HN=P(iBuNCH2CH2)3N (3a) in quantitative yield. Reaction of 3a with R'2PCl afforded sterically bulky electron-rich phosphines of the type R'2PN=P(iBuNCH2CH2)3N (4) [R'=Ph (4a), iPr (4b), tBu (4c)]. The Pd(OAc)2/4c catalyst system was particularly efficient for the coupling of arylboronic acids with aryl bromides as well as aryl chlorides to give biaryls in excellent yields.

Merrifield Resin-C6H4CH2N3P(MeNCH2CH2)3N: an efficient reusable catalyst for room-temperature 1,4-addition reactions and a more convenient synthesis of its precursor P(MeNCH2CH2)3N.

1,4-additions to a variety of Michael acceptors with a wide variety of donors were efficiently catalyzed at room temperature by the title reusable Merrifield resin-supported catalyst. Advantages of this catalyst include a simple workup (filtration of the reaction mixture) and good to excellent product yields. We also report a substantially simplified synthesis of the commercially available strong nonionic base 1, a precursor to the title polymer-bound catalyst.

Facile synthesis of monomeric alumatranes.

Alumatranes, tricyclic neutral molecules featuring a transannular N --> Al bond, can act as Lewis acids that activate substrates in the axial coordination site. Treatment of tris(2-hydroxy-3,5-dimethylbenzyl)amine with AlMe(3) afforded dimeric (AlL)(2) 1 [wherein L = tris(2-oxy-3,5-dimethylbenzyl)amine]. X-ray diffraction analysis revealed bridging between AlL monomers by two Al-O bonds.

Synthesis and photoelectron spectroscopic studies of N(CH2CH2NMe)3P=E (E = O, S, NH, CH2).

The synthesis and the crystal and molecular structure of N(CH(2)CH(2)NMe)(3)P=CH(2) is reported. The P-N(ax) distance is rather long in N(CH(2)CH(2)NMe)(3)P=CH(2). The ylide N(CH(2)CH(2)NMe)(3)P=CH(2) proved to be a stronger proton acceptor than proazaphosphatrane N(CH(2)CH(2)NMe)(3)P, since it was shown to deprotonate N(CH(2)CH(2)NMe)(3)PH(+).

3/2-order chain kinetics involving a postulated dicationic intermediate in the isomerization of a p-isocyano to a p-cyano azaphosphatrane monocation.

Kinetic evidence suggests the possibility of a dicationic intermediate in the title reaction. Thus the linkage isomerization reaction, PNC+ = PCN+, is described by the rate law, nu = 3/2k[PNC+]3/2, which can be interpreted by a chain mechanism with the propagation reaction PNC+ + P2+ --> P2+ + PCN+. Such propagation is unusual in that the intermediate regenerates itself in this single step rather than forming a different intermediate for a second propagation step.

A highly effective catalyst system for the Pd-catalyzed amination of vinyl bromides and chlorides.

[reaction: see text] A highly efficient synthesis of enamines and imines by Pd-catalyzed amination of vinyl bromides or chlorides with amines is described using the Pd2(dba)3/P(i-BuNCH2CH2)3N catalyst system.

Separation and characterization of underivatized oligosaccharides using liquid chromatography and liquid chromatography-electrospray ionization mass spectrometry.

Native cyclodextrin-based columns are particularly useful for the analysis of oligosaccharides because the retention of these carbohydrates is based mainly on the hydrogen bonding interactions of oligosaccharide hydroxyl groups with the stationary phase. Thus, the retention time predictably increases with the number of analyte hydroxyl groups, which corresponds to the elongation of the oligosaccharide chain. High-performance liquid chromatography (HPLC) coupled to electrospray ionization (ESI) mass spectrometry (MS) was used for the separation and characterization of underivatized oligosaccharide mixtures.

P(i-BuNCH2CH2)3N: an efficient promoter for the nucleophilic aromatic substitution reaction of aryl fluorides with aryl TBDMS (or TMS) ethers.

[reaction: see text]. The nucleophilic aromatic substitution reaction between electron-deficient aryl fluorides and aryl TBDMS (or TMS) ethers has been shown to be efficiently promoted by proazaphosphatranes such as P(i-BuNCH(2)CH(2))(3)N (3). Excellent yields of diaryl ether products were obtained under unusually mild conditions.