@article {50162,
	title = {Reactions of saturated NHC{\textperiodcentered}boranes with electron-deficient alkynes and alkenes. borirane formation, their reactivities, and coupling of tetracyanoethylene},
	journal = {Dalton Transactions},
	volume = {55},
	year = {2026},
	month = {JUN},
	pages = {8356-8365},
	type = {Article},
	abstract = {<p>
	In this study, we describe the reactions of five- and six-membered saturated N-heterocyclic carbene boranes (NHC \&amp; centerdot;BH3) with electron-deficient alkenes and alkynes. Notably, both five- and six-membered saturated NHCs form boriranes upon the reaction of NHC \&amp; centerdot;BH3 with dimethyl acetylene dicarboxylate (DMAD). However, their reactivity with HCl differs: the five-membered saturated NHC-stabilized borirane undergoes ring opening in toluene/THF, whereas the six-membered saturated NHC-stabilized borirane undergoes ring expansion, forming exclusively a boralactone irrespective of solvent. Interestingly, when acetonitrile is used as a solvent, the five-membered saturated NHC-stabilized borirane yields both ring-opening and ring-expansion products. To remove the hydrogen attached to the boron atom in boriranes, we reacted the five-membered saturated NHC-stabilized borirane with AlCl3 and B(C6F5)(3), resulting in azaborolium cation or adduct formation, respectively. Transitioning from an electron-deficient alkyne to an alkene, the reaction of six-membered saturated NHC \&amp; centerdot;BH3 with tetracyanoethylene (TCNE) led to the unusual coupling of two TCNE molecules.</p>
},
	issn = {1477-9226},
	doi = {10.1039/d6dt00852f},
	author = {Amrutha, P. R. and Kundu, Gargi and Ganesh, Vemuri Lakshmi and Gonnade, Rajesh G. and Gopakumar, Gopinadhanpillai and Sen, Sakya S.}
}
