The present is the first of a series of papers describing new developments in the methods of preparation and in the chemistry of diborane and of the borohydrides. New and practical methods for the preparation of borohydrides (a) from diborane, and (b) without the use of diborane are discussed. As a result of the availability of borohydrides, prepared without the use of diborane, methods, far more satisfactoiy than those hitherto known for the preparation of the latter, have been developed. The investigation has led to the preparation of the hitherto unknown borohydrides of sodium, of potassium and of uranium, and some of their derivatives, as well as of a new type of substance, such as sodium trimethoxyborohydride, NaBH(OCH3)3, formed by the addition of compounds of trivalent boron to alkali metal hydrides. Sodium borohydride, as well as sodium trimethoxyborohydride, are of special interest because of their potential usefulness as reducing agents and sources for the generation of hydrogen; uranium(IV) borohydride and its derivatives are of interest because they are the most volatile compounds of uranium except the hexafluoride. The present paper surveys numerous new observations made and organizes the subject matter in the light of the principle which largely guided the research, namely, the application of the Lewis generalized acid-base concept to the reactions of diborane, of the salt-like hydrides and of the borohydrides. Detailed description of the new preparative methods and data confirming the reaction equations herein presented as well as supporting the composition of new substances are deferred to the remaining papers of the series.vestigations carried out under contracts with the National Defense Research Committee, with the Office of Scientific Research and Development and with the Signal Corps, Ground Signal Agency during the years 1940-1944. They were continued under Navy auspices during [1944][1945][1946]. Most of the results were originally described in the final reports on contracts NDC-rc-56, 9820 and 10,421.

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Optimum conditions for operating the arc method for the preparation of diborane are very briefly outlined as are improvements in the procedure which reduce the amount of liquid nitrogen and decrease greatly the time required for the generation of diborane. The use of pyridine in separating diborane from hydrogen halides and other impurities is described.

1,4-Naphthoquinones have been known to possess a wide spectrum of biological activities such as antidiabetic, antibacterial, antimalarial, anticancer and antifungal activities. An efficient, environmentally friendly two step process for synthesizing various 2-substituted 1,4-naphthoquinones is described, starting from 2-bromonaphthalene and olefinic substrates using the Heck reaction in an ionic liquid (IL) followed by oxidation. It provides for a rapid and "green" methodology for the synthesis of the biologically active 2-substituted 1,4-naphthoquinones.