02304nas a2200229   4500008004100000022001400041245011900055210006900174260000900243490000700252520151600259653001001775653002401785653002701809653001901836653001301855100001701868700002001885700001901905700001901924856013101943       2024                        eng d  a0947-653900aAccess to NHC-Boryl mono- and bis-selenide and utility as mild selenium transfer reagent including to the C-F bond0 aAccess to NHCBoryl mono and bisselenide and utility as mild sele  cJAN 0 v303 a<p>
	Reactions of 5-SIDipp &amp; sdot; BH3 (5-SIDipp=1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene) (1) with diphenyldiselenide provide access to 5-SIDipp-boryl mono- (5-SIDipp &amp; sdot; BH2SePh) (2) and bis-selenide (5-SIDipp &amp; sdot; BH(SePh)2) (3). The facile cleavage of the B-Se bond makes 2 a neutral source of selenium nucleophiles in substitutions reactions with benzyl bromides, and provide access to the corresponding selenoethers. The direct transformations of one of the C(sp2)-F bonds of C5F5N and C6F5CF3 to C-Se bonds have also been achieved by the use of 2 without employing transition-metal catalysts. While it was previously established that C6F6 could undergo complete defluoroselenation under harsh conditions, we successfully achieved partial defluorination of C6F6 by employing 2 as a mild selenide transfer reagent. During the formation of C-Se bonds through the cleavage of C-F bonds, the potential by-product NHC &amp; sdot; BH2F undergoes ring expansion of the NHC, leading to the formation of the six-membered diaazafluoroborinane (7). Access to NHC &amp; sdot; boryl mono- and bis-selenides from NHC &amp; sdot; BH3 has been achieved. The boryl mono selenide has been demonstrated to function as a selenium transfer reagent, enabling the synthesis of selenoethers from benzyl bromide. Additionally, it can also facilitate the conversion of the challenging aromatic C-F bond to a C-Se bond, resulting in concomitant ring expansion of NHC &amp; sdot; haloborane.image</p>
10aboron10aC-F Bond Activation10aN-Heterocyclic carbene10aRing expansion10aSelenium1 aKundu, Gargi1 aAmrutha, P., R.1 aTothadi, Srinu1 aSen, Sakya, S.  uhttps://library.ncl.res.in/content/access-nhc-boryl-mono-and-bis-selenide-and-utility-mild-selenium-transfer-reagent-including