Robert O. Hutchins

Reductive displacement of allylic acetates by hydride transfer via catalytic activation by palladium(0) complexes

Abstract Allylic acetates are reduced to alkenes by reductive displacement by hydride reagents via catalytic activation with Pd(0) complexes. In the absence of hydrides, allylic acetates afford conjugated dienes in DMSO solvent.

Reduction of C N to CHNH by Metal Hydrides

The reduction of various carbon–nitrogen π-systems to saturated derivatives with metal hydrides, principally aluminum- and boron-based reagents, provides highly useful processes for the preparation of amines and related functionalities.

μ-Bis(cyanotrihydroborato)-tetrakis(triphenylphosphine) dicopper(I). A new, selective, pH dependent reducing agent

Abstract The title compound selectively reduces acid chlorides to aldehydes under neutral conditions and aldehydes and ketones to alcohols in acidic media. 4- tert -Butylcyclohexanone is reduced to the trans alcohol with a high degree of stereoselectivity (94:6).

Reduction of C X to CH 2 by Wolff–Kishner and Other Hydrazone Methods

Since its introduction early in this century,1,2 the deoxygenation of aldehydes and ketones to methyl or methylene derivatives, respectively, via base treatment of hydrazone intermediates (equation 1) has proven to be one of the most convenient and synthetically useful processes available for this important type of transformation. The reaction is termed the Wolff–Kishner reduction in recognition of the two original independent discoverers.1,2 However, the initial recipes introduced proved tedious and unreliable with many structural, especially hindered, examples. This led to substantial efforts devoted over the years to developing more convenient and successful experimental procedures, resulting in a number of improved and more reliable modifications which are most often utilized at present. More recently, modified procedures have been provided which utilize hydride reductions of p–toluenesulfonylhydrazone (to– sylhydrazone) derivatives and subsequent decomposition to release the hydrocarbon products under much milder and less basic conditions than those normally required for Wolff–Kishner reductions (equation 2).

Reductions of Alkyl and Aryl Halides with Magnesium and Methanol

Abstract The combination of magnesium in methanol provides a convenient, efficient system for the selective hydrogenolysis of alkyl and aryl iodides and bromides. Vinyl bromides are also reduced if conjugated to an aromatic ring while only benzylic, allylic and naphthalenic chlorides are affected. Deuterium may be selectively introduced via utilization of methanol-d as solvent.

Selective reductions of conjugated acetylenes with magnesium in methanol and methanol-D

Abstract The combination of magnesium in methanol or methanol-d offers an efficient, convenient and selective method for reduction of acetylenic bonds conjugated to esters (but not acids) or to two phenyl groups to the saturated or tetradeuterated derivatives, respectively.

Highly diastereoselective reductions of N-diphenylphosphinyl imines. Synthesis of axial primary cyclic amines.

Abstract The reduction of N-diphenylphosphinyl imines of substituted cycloalkanones with lithium tri-sec-butylborohydride provides highly diastereoselective conversions to protected axial primary amines which are demasked via cleavage with acid.

Cyanoborohydride supported on an anion exchange resin as a selective reducing agent

Ion-exchange resin bound cyanoborohydride provides a successful and convenient reagent for a variety of reductions with the added advantages of ease of work up and resin retention of cyanide.

An Efficient Approach to Spirosesquiterrenes. Synthesis of (±)β-Vetivone.

Abstract (±)β-Vetivone and (±) 10-epi-β-vetivone have been synthesized in 6 steps via an efficient spiroannelation-functionalization sequence.

Synthesis and characterization of diethylmethylene diphosphonato metal complexes

Reactions of tetraethylmethylene diphosphorate (TEMDP) with metal chlorides at elevated temperatures lead to the formation of complexes of the types M(L)(LH)(M = Al, Ti, V, Cr, Fe, Dy); M(L)(LH)/sub 2/M = Th, U) and M/sub 2/ (L)(LH)/sub 2/(M = Co, Ni), where L is the diethylmathylene diphosphonato (DEMDP) ligand. The new complexes are insoluble in all common organic solvents and do not melt or decompose at temperatures up to 300 to 350 deg C; furthermore, the Ti(III), V(III), Cr(III), Fe(III) and U(IV) complexes exhibit subnormal magnetic moments. These properties are strongly in favor of polynuclear structures. Spectral and magnetic studies suggest that the M(III) complexes are distorted octahedral, the M(II) compounds pentacoordinated, with a low symmetry square pyramidal oonfiguration, and the M(IV) complexes octa- or ennea-coordinated. DEMDP acts as a tridentate bridging ligand, involving an uncoordinated P = O group, whereas its monoprotonated derivative also acts as tridentate in the M(III) Complexes; in the M(II) and M(IV) complexes one LH ligand acts as tridentate, while the other is, most probably, bidentate. Possible structures for the new complexes and the nature of the synthetic reactions are discussed. (auth)