The development of several new procedures for highly selective organic synthesis via organic “ate” complexes including lithium, copper, boron, aluminum, and palladium is described. Dialkenylchloroboranes (1) react with 3 molar equivalents of methylcopper to produce symmetrical (E, E) -1, 3-dienes in high yields. It is revealed that the reaction involves the alkenylcopper-boron complex (loose “ate” complex), free alkenylcopper, and/or copper alkenylborate (tight “ate” complex) as the intermediates. These intermediates further react with allylic halides or alkyl halides to produce stereoselectively E-1, 4-dienes or olefins, respectively. New organocopper reagents, such as RCu·BF3 and RCu·BR3, are developed. Complete γ-attack toward allylic halides, direct alkylation of alcohols, and 1, 4-addition to previously unreactive substituted enoate esters and enoic acids are realized by using the former reagent. Stereocontrolled cis-addition to α, β-acetylenic carbonyl derivatives is achieved by using the latter reagent. Regiocontrolled head-to-tail coupling of allylic boron “ate” complexes with allylic halides is accomplished. Complete control to the regiochemistry in the reaction of heteroatom substituted allylic carbanions is realized with the allylic aluminum “ate” complexes which are formed by the addition of triethylaluminum to the carbanions. The stereoselective olefin synthesisvia the reaction of alkenylboranes with palladium acetate is developed.
Recently 2-alkoxy-1, 3-benzodithioles have become readily obtainable by the reaction of benzyne (conveniently generated frome anthranilic acid) on carbon disulfide in the presence of alcohols, and thus now 1, 3-benzodithiolylium salts can be easily prepared from them. Recent synthetic studies with these reagents are reviewed. The review also includes the problem of aromaticity of 1, 3-benzodithiolylium salts and related compounds.
In general, it is difficult to prepare an aromatic aldehyde by the liquid-phase autoxidation of the corresponding toluene derivative because the aldehyde once formed is immediately oxidized to the carboxylic acid. The present author and his co-workers have been trying to prepare an aromatic aldehyde by the autoxidation of the corresponding toluene derivative, and have succeeded in obtaining the aldehyde with a good yield. Therefore, the author's works on the synthesis of aromatic aldehydes by autoxidation are reviewed in some detail covering the following subjects : synthesis of hydrocarbyloxy benzaldehydes by liquid phase autoxidation of hydrocarbyloxy toluenes in acetic acid in the presence of cobalt acetate, synthesis of substituted benzaldehydes by liquid phase autoxidation of substituted toluenes in acetic acid in the presence of cobalt acetate and sodium bromide. To clarify the description of the author's works, a brief survey on the industrial routes and use of aromatic aldehydes, especially benzaldehyde, anisaldehyde, and m-phenoxybenzaldehyde, is given. Benzaldehyde is the simplest aromatic aldehyde, anisaldehyde is produced in the highest yield with the author's method and m-phenoxybenzaldehyde is one of the key elements of the insecticides named “synthetic pyrethroides”.
The reaction mechanisms of the O-O cleavage of organic peroxides, hydrogen peroxide, hydroperoxides, dialkyl peroxides, peracids, peroxyesters, and diacyl peroxides, have been explained on the basis of their HOMO and LUMO and on the basis of the potential surfaces along the reaction paths. The discussion covers the electronic structure and conformation of the peroxides, the characteristics of HOMO and LUMO of the peroxides, the reaction with nucleophiles and with electrophiles, homolytic decomposition process, radical-induced decomposition, and the electronic structure of the radicals produced from the O-O cleavage.
During these two or three years, reactions which are carried out with the use of reagents adsorbed on alumina or silica gel have increasingly appeared and many compounds have become accessible in much simpler synthetic procedures. This new method for organic synthesis is based on the reasoning that high reactivities of reagents are reduced or adjusted by adsorption to produce high selectivity of reagents. Usually these reactions proceed selectively, cleanly, and give products in high yields. In some cases ordinary reaction of the reagent is completely inhibited by alumina or silica gel and a new reaction appears. These newly developed reactions are reviewed here, mainly from the standpoint of organic synthesis.
The biosynthesis of corrin was examined in a new light using 13C-labeling and NMR techniques which added a new dimension to the chemists' armamentarium and opened a new era in the study of the biogenesis of the complicated cobalamin. The use of 13C-FTNMR has led to the observation that 8 molecules of [2-13C] ALA are incorporated into vitamin B12, [5-13C] ALA labels seven only of the carbon atoms cyanocobalamin, i.e. amino methyl groups of ALA is 'lost' the process. It has also been confirmed that seven of the methyl groups of B12 are derived from [13CH3] -methionine and further that the chirality of the gemdimethyl grouping at C12 labelled with [13CH3] -methionine is R. Four [8-13C] -PBG were incorporated into V.B12 giving rise to 4 centers of enriched carbons. Mutiply-labelled uro'genIII (13C, 14C and 3H) has been used to show that incorporation takes place without randomization. A sequence for corrin synthesis from uro'genIII is presented. Also this review is shown more recently results in the corrin pathway.
Recent activities and progress in the field of research and development of color photographic materials are reviewed in the following items ; 1. Product-target setting 2. Technical problems. -complexity of the system based on various fields of science and technology- 3. Organizing the R. and D. activities.