Alkylations reductive

The Reissert method15—conversion of an isoquinoline to a 2-benzoyl-1,2-dihydroisoquinaldonitrile (Reissert compound), alkylation, and hydrolysis—has enjoyed wide success in the synthesis of benzyliso-quinoline and related alkaloids.16,17 In particular, aporphines are prepared conveniently by converting isoquinolines to I-(o-nitrobcnzyl)-isoquinolines via a Reissert sequence, followed by A7-alkylation, reduction, and Pschorr cyclization.17... 

This procedure illustrates a general method for preparing aromatic hydrocarbons by the tandem alkylation-reduction of aromatic ketones and aldehydes.2 Additional examples are given in Table I. 

White-rot fungus has been used as a biocatalyst for reduction and alkylation. The reaction of aromatic -keto nitriles with the white-rot fungus Curvularia lunata CECT 2130 in the presence of alcohols afforded alkylation-reduction reaction [291]. Alcohols such as ethanol, propanol, butanol, and isobutanol could be used (Figure 8.39d). 

Keywords Cyanohydrin acetonide alkylations. Reductive decyanations, Oxocarbenium ions. Reductive lithiation... 

During the course of the development of our group s alkylation/reductive decyanation strategy, a very reliable method for distinguishing between syn-and anfz-l,3-diols was discovered [17,18]. The acetonide methyl groups reliably display diagnostic C-NMR chemical shifts, allowing for stereochemistry to be determined simply by inspection (Fig. 1). Evans later extended the C-NMR chemical correlation to polypropionate chains [19,20]. 

A recent interesting example of the chiral amplification of a small initial e.e. has been reported by Soai et al. [113,114] involving the induction of a chiral center in an achiral aldehyde using diisopropylzinc as an alkylating reductant and a very small... 

Pyrrolo[l,2-(7][l,2,5]benzotriazepin-ll-one 329 is the product of a sequence starting from N-(2-nitrophenyl)-lH-pyrrol-l-amine 327. The pathway included alkylation, reduction of the nitro group, formation of the isocyanate from intermediate 328 and intramolecular thermal cyclization (Scheme 69 (2000JHCl539)). 

Sultines can be versatile synthetic intermediates for example, they undergo ring-opening reactions, alkylation, reductive desulfurization , and oxidation at sulfur to give sultones. 

Acylations, Alkylations, Reductive Alkylations (Aminations, Alkaminations)... 

Selective reductions.1 Zinc bo and a,P-enals at -15° without effc Reduction of azomethines.s Z ary amines or the amine-BH3 compfc alkylation-reduction of nitriles to j... 

Reduction of azomethines,3 Zn(BH4)2 in ether reduces Schiff bases to secondary amines or the amine BH3 complex in high yield. This procedure can be applied to alkylation-reduction of nitriles to yield 1-phenylalkylamines. 

Fig. 2. Fluorous biphasic catalysis part II asymmetric alkylation, reduction, oxidation, and cross-coupling reactions with fluorous tagged catalysts.

The essence of the cascade synthesis is depicted in Scheme 2.1. Two procedures, alkylation and reduction, comprised the [a — b — a — b — ] sequence. Thus, treatment of a diamine with acrylonitrile afforded tetranitrile 3. Cobalt-mediated nitrile reduction gave tetraamine 4. Further amine alkylation provided the second generation octanitrile 5. The nonskid-chain-like [2] synthesis is shown in Scheme 2.2. Construction of polycyclic 6 was accomplished by repetitive alkylation, reduction, acylation, and reduction (a — b c— d—>a- b— ...) sequences. Again, repetitive and multiple reaction sequences were employed for the generation of new molecular assemblies. Most notable about these syntheses is that for the first time, generational molecules were prepared and characterized at each stage of the construction process. 

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