Boron-sulfur bonds

The most widely used method for the synthesis of iminoboranes involves the 1,2-addition of boron-element bonds such as boron-hydrogen, boron-halogen, boron-carbon, or boron-sulfur bonds across the C=N bond of nitriles thereby producing variously substituted iminoboranes (Eq. (2)). The formation of iminoboranes as well as the stability of the products depends on the substituent on the nitrile group, the nature of the boron-element bond to be cleaved during the 1,2-addition across the C N bond, and to a lesser extent on the non-reacting boron substituents 26T... 

Boron-sulfur bonds, addition, to alkynes, 10, 778 Boron trihalides, in boron compound synthesis, 9, 146 Boron-zinc exchange and copper-catalyzed substitutions, 9, 518 for organozinc halide preparation, 9, 89 Borostannylation, enynes, 10, 334... 

Element-element bonds, addition to G-G multiple bonds arsenic—selenium bonds, 10, 782 boron—boron bonds, 10, 727 boron—sulfur bonds, 10, 778 B-S and B-Ge bonds, 10, 758 chalcogen—chalcogen additions, 10, 752 germanium—germanium bonds, 10, 747 germanium-tin bonds, 10, 780 overview, 10, 725-787 phosphorus—phosphorus bonds, 10, 751 phosphorus—selenium bonds, 10, 782 phosphorus-sulfur bonds, 10, 781 Se-Si and Se-Ge bonds, 10, 779 silicon-germanium bonds, 10, 770 silicon-phosphorus bonds, 10, 780 silicon-silicon bonds, 10, 734 silicon-sulfur bonds, 10, 779 silicon-tin bonds, 10, 770 tin-boron bonds, 10, 767 tin-tin bonds, 10, 748... 

Exchange of boron-oxygen bonds with boron-sulfur bonds has been investigated 178) in the systems described by Eqs. (86)-(89), where X and Y... 

Recently, interest in copper-catalyzed carbon-heteroatom bond-forming reactions has shifted to the use of boronic acids as reactive coupling partners [133], One example of carbon-sulfur bond formation is displayed in Scheme 6.65. Lengar and Kappe have reported that, in contrast to the palladium(0)/copper(l)-mediated process described in Scheme 6.55, which leads to carbon-carbon bond formation, reaction of the same starting materials in the presence of 1 equivalent of copper(II) acetate and 2 equivalents of phenanthroline ligand furnishes the corresponding carbon-sulfur cross-coupled product [113]. Whereas the reaction at room temperature needed 4 days to reach completion, microwave irradiation at 85 °C for 45 min in 1,2-dichloroethane provided a 72% isolated yield of the product. 

The carbon-sulfur bond of thiazines can be reductively cleaved (Sections 7.06.5.7 and 7.06.6.7) and 2//-thiazines, being imines, can be hydrolyzed (Section 7.06.5.5). Saturated thiazines (thiomorpholines) are stable toward alkaline hydrolysis <1981CPB1554> and Lewis-acidic boron trifluoride <1980JHC449>. 

Compounds containing the boron-chalcogen bond, in Handbook of Chal-cogen Chemistry New Perspectives in Sulfur, Selenium and Tellurium, ed. F. A. Devillanova, Royal Society of Chemistry, Cambridge, 2007, pp. 17-19. 

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