Tris ketimine

Using sulfide contraction, the ring b and c precursors were linked together (Scheme 40) to afford (396) as a 2 1 mixture of two crystallizable epimers. The ring d bromide (397) (obtained by bromination of the ketimine) condensed smoothly with the thiolactam (396) in the presence of butoxide to give (398) after sulfide contraction using tris(2-cyanoethyl)phosphine and TFA. The thiolactone obtained by treatment of (398) with phosphorus pentasulfide was next treated with dimethylamine in methanol and thereby introduced an exocyclic double bond, as shown in (399). 

A benzene solution of the ketimine (0.01 M) was warmed to 85 °C in a round-bottomed flask equipped with a condenser. A 1 ml benzene solution of tri-n-butyltinhydride (1.1 eq) and azodiisobutylnitrile (0.4 eq) was loaded into a gas-tight syringe and attached to... 

Bis(imino) thietanes, 343, 344, are prepared by reaction of isonitriles with iminothiiranes or of ketenimines with p-tolylsulfonyl isothiocyanate. Reaction of phosphonium ketimine ylides, for example, 312, and related compounds with isothiocyanates also gives bis(imino) thietanes, for example, 345. " Treatment of arylsulfonyl isothiocyanates with trimethylacetoisonitrile yields tris(imino)-thietanes, for example, 341. ... 

For the synthesis of tris (TMS)-ketimine (448), acetonitrile (386a) is lithiated with t-butyllithium and then converted into 448 as a by-product [bis(TMS)amino]-TMS-acetylene (449) occurs (equation 208)228. In addition, tris(TMS)-ketimine (448) can be... 

In addition, the asymmetric reduction of A7-aryl ketimines with tri-chlorosilane could be achieved on polymer-supported organocatalysts by Kocovsky et alP Indeed, 7V-methylvaline-derived formamide anchored to a polymeric support, used at a catalyst loading of 15 mol %, allowed good enantioselectivities of up to 82% ee combined with good yields to be obtained for the formed chiral amines (Scheme 8.3). This novel methodology simplified the recovery of the catalyst, which could be reused at least five times without any loss of the activity. The best results were obtained with the catalysts directly attached to the polymer or via a suitable spacer. A strong influence of the solvents on the catalytic performance was observed with chloroform giving the... 

The catalytic asymmetric /-selective Diels-Alder annulation of a, -unsaturated /-butyrolactams with enones provided a synthesis of, y-functionalized bridged bi-or tri-cyclic dihydropyranopyrrolidin-2-ones in one step (up to 98% yield, >20 1 dr, and 99% ee) The inverse-electron-demand aza-Diels-Alder cycloaddition 0 of A-aryl-a,/0-unsaturated ketimines with enecarbamates in the presence of chiral bifunctional phosphoric acids produced 4,5,6-trisubstituted 1,4,5,6-tetrahydropyridines having three contiguous stereogenic centres in up to 84% yield, 95 5 dr, and 95% 5-Alkenylthiazoles react as in-out dienes with e-poor dienophiles in polar 44-2- 0 cycloaddition reactions. The cycloadditions are site selective. The mechanism is thought to lie between a concerted but highly asynchronous process and a stepwise process. 

Recently, Yamakawa and Yoshikai attempted to extend this chemistry to aryl aldimines. Limited success was achieved under the reaction conditions previously reported for aryl ketimines. However, careful screening and re-optimization of the reaction conditions eventually led to the desired addition products 28-33 in modest yields when tris(3-methylphenyl)phosphane (P(3-CH3QH4)3) and l-PrMgBr were used instead of P(3-C1C6H4)3 and t-BuCH2MgBr. 

N-Organosilyl Imines and Imides This group of compounds includes the organosilyl derivatives of ketenimines, ketimines, sulphodiimines, carbodiimides, iminophos-phoranes, etc. Tris(trimethylsilyl)ketenimine [380] (85% b.p. 65-70°C at 0.13 kPa = 1 mm Hg) is prepared from acetonitrile, r-butyllithium and chlorotrimeth-... 

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