Highly Colored Boron‐Doped Thiazolothiazoles from the Reductive Dimerization of Boron Isothiocyanates

Abstract

Reduction of (CAAC)BBr2(NCS) (CAAC=cyclic alkyl(amino)carbene) in the presence of a Lewis base L yields tricoordinate (CAAC)LB(NCS) borylenes which undergo reversible E/Z‐isomerization. The same reduction in the absence of L yields deep blue, bis(CAAC)‐stabilized, boron‐doped, aromatic thiazolothiazoles resulting from the dimerization of dicoordinate (CAAC)B(NCS) borylene intermediates.

Adducts of the Parent Boraphosphaketene H2BPCO and their Decarbonylative Insertion Chemistry

“…phaketene 2 a with boroles [RBC 4 Ph 4 ] (R = Ph, 2-thienyl, Mes) at room temperature led to the decarbonylative insertion of the phosphinidene [(CAAC Me )(H) 2 B À P] into the borole ring and isolation of yellow solids 4 a-c in good yields (86-93 %; Figure 3). The 1,2-phosphaborinines 4 a-c show moderate deviation in the 11 Disorder present in the central C 4 BP ring of the solid-state structure of 4 a prevents detailed analysis of the endocyclic metrical parameters, but unambiguously confirmed the identity of the 1,2-phosphaborinine 4 a (see Figure 3). 4 a displays a planar C 4 BP unit with five phenyl groups oriented in a propeller-like fashion, as frequently observed for their BN homologues, 1,2-azaborinines.…”

“…The half-sandwich complexes 5 a-c were isolated as yellow solids in good to excellent yields (83-94 %). The 11 ]. [17] The significant upfield shift of the 31 P NMR signal (5 a: ) that are significantly lower in frequency than those of Martins thiaborinineÀ Cr(CO) 3 complex (ñ(CO) = 1964, 1908, 1873 cm À1 ) as well as those of a 1,2-azaborinine chromium complex (ñ(CO) = 1979, 1916, 1900 cm À1 ) reported by Ashe, [17,18] implying much stronger backdonation from the 1,2-phosphaborinine-metal fragment into the p* orbitals of the CO ligands.…”

Reactivity of cyano- and isothiocyanatoborylenes: metal coordination, one-electron oxidation and boron-centred Brønsted basicity

“…and Y is an anionic substituent ( e.g. aryl, 9 amino, 8 boryl, 10 H, 10 a ,11 F, 12 Cl, 13 CN, 14 NCS, 15 etc. ).…”

Intensiv farbige Bor‐dotierte Thiazolthiazole durch reduktive Dimerisierung von Borisothiocyanaten

“…Kristallographisch ermittelte Festkçrperstrukturen von a) (Z)-2 Me (nur eines der beiden Moleküle in der asymmetrischen Einheit ist abgebildet) und b) (E)-2 Cy . [38] Atomverschiebungsellipsoide auf eine Wahrscheinlichkeit von 50 % eingestellt. Ellipsoide der Ligandenperipherie und Wasserstoffatome sind nicht abgebildet.…”