Aluminum imide

The dimers have a four-membered A12N2 ring (6-XV) which may have isomers if the groups are different. The aluminum imides [RA1(NR )] usually have cubane or larger cage structures (6-XVI) trimers (e.g., the alumazene 6-XVII) and heptamers have also been found, depending on the size of R and R and the reaction conditions.29... 

Combination of tris-ethylaminoborane and diethyl aluminum amide at 3 1 mol ratio affords a homogeneous liquid phase mixture. The % NMR spectrum of the mixture indicates that the two components do not react with each other at room temperature. When heated to 100 °C, the mixture gives off ethylamine and ethane to yield a viscous cloudy liquid 1. The turbidity is probably caused by the partial decomposition of the diethyl aluminum amide into the oligomeric ethyl aluminum imide, which is insoluble in common organic solvents [8,9]. The NMR spectram of the viscous liquid shows that most of (Et2AINH2)3 has either reacted to give new compound 2 or decomposed to the imide, but that some (EfNH)3B still remains. The new compound 2, isolated... 

Aluminum Amides, Aluminum Imides, and Aluminum Nitride Al-N Bonds with Partial Dative Character... 

A key step in the synthesis of the spiroketal subunit is the convergent union of intermediates 8 and 9 through an Evans asymmetric aldol reaction (see Scheme 2). Coupling of aldehyde 9 with the boron enolate derived from imide 8 through an asymmetric aldol condensation is followed by transamination with an excess of aluminum amide reagent to afford intermediate 38 in an overall yield of 85 % (see Scheme 7). During the course of the asymmetric aldol condensation... 

The same auxiliary at nitrogen is used in the diastereoselective reduction of a series of bicyclic imides with sodium bis(2-methoxyethoxy)aluminum hydride or sodium diethylalu-minum hydride at — 78 "C, proceeding in 85-97% yield45 with d.r. values >75 25. 

Bidret, 1 -PHENY L-2-THIO-, 42, 87 Brominadon, nuclear, aluminum chloride as catalyst for, 40, 7 of cyclopropanecarboxylic acid to bromocvclopropane, 43, 9 of phthalide using N-bromosuccin-imide, 42, 26... 

A chiral aluminum-salen catalyst gives good enantioselectivity in the addition of cyanide (from TMS-CN) to unsaturated acyl imides.338... 

Sulfonamide derivatives of a-amino acids and the similar bissulfonamide derivatives of diamines can be used to prepare reactive Lewis acid complexes. Corey20 reported the Lewis acid (R,R)- or (5,5 )-complex 69, which can be employed at 10 mol% level to catalyze the Diels-Alder reaction of cyclopentadiene and imide. Reactions catalyzed by this complex give an endo.exo ratio of over 50 1, as well as a high ee (91%) at —78°C, and this can be further improved to 95% by carrying out the reaction at 90°C.20 The related aluminum complex 69b shows very similar reactivity at —78°C, with generally higher ee values, typically over 95%, for the reaction of cyclopentadiene derivatives with imide.20,21... 

Alkaline s2 xxiifications of the four graft copolymers of Table VI were next carried out to determine the influence of mole % AASO3H on absorbent properties of final products. Se xxiifications were carried out imider the conditions described in Table V and in addition to a control product isolated with no aluminum treatment. 

Almost all organic functional groups except for olefinic double bonds are reduced by hthium aluminum hydride. It reduces acids, esters, acid chlorides, amides, imides, imines, nitriles, nitroorganics, epoxides, and lactones. 

A different approach to enantiotopic group differentiation in bicyclic anhydrides consists of their two-step conversion, first with (/ )-2-amino-2-phcnylethanol to chiral imides 3, then by diastereoselective reduction with sodium bis(2-methoxyethoxy)aluminum hydride (Red-Al) to the corresponding chiral hydroxy lactames 4, which may be converted to the corresponding lactones 5 via reduction with sodium borohydride and cyclization of the hydroxyalkyl amides 101 The overall yield is good and the enantioselectivity ranges from moderate to good. Absolute configurations of the lactones are based on chemical correlation. 

Much the same activity is retained when the nitrogen atoms in the heterocyclic nucleus are shifted around. The convergent scheme to this related compound starts with the acylation of alanine (35-1) with butyryl chloride (35-2). The thus-produced amide (35-3) is then again acylated, this time with the half-acid chloride from ethyl oxalate in the presence of DMAP and pyridine to afford the intermediate (35-4). In the second arm of the scheme, the benzonitrile (35-5) is reacted with the aluminate (35-6), itself prepared from trimethyl aluminum and ammonium chloride, to form the imidate (35-7). Treatment of this intermediate with hydrazine leads to the replacement of one of the imidate nitrogen atoms by the reagent by an addition-elimination sequence to form (35-8). Condensation of this product with (35-4) leads to the formation of the triazine (35-9). Phosphorus oxychloride then closes the second ring... 

Reduction of a chiral imide (2).1 Highly selective reduction is possible for the chiral protected ci s-dihydroxytartarimide 2 with this reagent (equation I). Lithium aluminum hydride shows only slight diastereoselectivity (22%), and use of SMEAH provides 3 in about 64% de. However, tetramethylammonium triacetyxyborohydride... 

Boric acid in conjunction with APP was reported in epoxy intumescent coating.30-31 Boric acid and its derivatives were used in phenolics to impart thermal stability and tire retardancy. For example, Nisshin steel claims the use of boric acid and aluminum trihydroxide (ATH) in phenolics for sandwich panel.32 It was also reported that the small amounts of boric acid (around 0.25% by weight) in polyether imide (PEI) and glass-filled and PEI can reduce peak HRR by almost 50% in the OSU Heat Release test for the aircraft industry.33 In applications where high modulus and high strengths are needed, boric acid can be added without the softening effects of other additives such as siloxanes. 

The compounds, silver imide and aluminum nitride, are largely covalent but hydrolysis of either yields ammonia, just as do the hydrolyses of the ionic compounds sodamide or magnesium nitride thus none of these compounds is stable in the presence of moisture. Since water is a stronger... 

---