The reaction of Fc # BBr 2 with 2 equiv of Et 3 SiH gives the boron-bridged dinuclear species Fc # 2 BBr with concomitant liberation of B 2 H 6 (Fc # = (C 5 Me 5 )Fe(C 5 H 4 )). The transformation is slow (48 h) but nevertheless provides yields of >85%. Fc # 2 BBr can conveniently be converted into the aminoborane Fc # 2 BNMe 2 by treatment with Me 3 SiNMe 2 . For an X-ray crystal structure analysis, Fc # 2 BNMe 2 was hydrolyzed to the borinic acid Fc # 2 BOH. A cross-coupling experiment using Et 3 SiH and an equimolar mixture of FcBBr 2 and Fc # BBr 2 led to the formation of the mixed product Fc(Fc # )BBr with high selectivity (Fc = (C 5 H 5 )Fe(C 5 H 4 )). Similar to the case for Fc # 2 BBr, Cym 2 BBr can be prepared from CymBBr 2 and Et 3 SiH (Cym = (OC) 3 Mn(C 5 H 4 )). In contrast to FcBH 2 , which exists only as transient intermediate on the way to Fc 2 BH, CymBH 2 is an isolable species. The compound was synthesized from a concentrated toluene solution of CymBBr 2 and excess neat Et 3 SiH at -78 °C and forms B-H-B-bridged dimers (CymBH 2 ) 2 in the solid state (X-ray crystallography). Our reactivity studies indicate that the Et 3 SiH-induced coupling reaction of derivatives L n M-(C 5 H 4 BBr 2 ) is fastest for electron-rich cyclopentadienyl complexes. Addition of NMe 2 Et to (CymBH 2 ) 2 affords the monomeric amine adduct CymBH 2 (NMe 2 Et). The reaction of (CymBH 2 ) 2 with HCC t Bu in a stoichiometric ratio of 1:4 (or slightly higher) results in a mixture of products from which the dinuclear hydroboration product (CymB(C(H)dC(H) t Bu)) 2 C(H)-C(H) 2 t Bu could be isolated and structurally characterized. To obtain the divinylborane CymB(C(H)dC(H) t Bu) 2 in high yield and pure form, (CymBH 2 ) 2 has to be dissolved in excess neat HCC t Bu.

A series of tetraaryl bisdiazaphospholane (BDP) ligands were prepared varying the phosphine bridge, backbone, and substituents in the 2-and 5-positions of the diazaphospholane ring. The parent acylhydrazine backbone was transformed to an alkylhydrazine via a borane reduction procedure. These reduced ligands contained an all sp 3 hybridized ring mimicking the all sp 3 phospholane of (R,R)-Ph-BPE, a highly selective ligand in asymmetric hydroformylation. The reduced bisdiazaphospholane (red-BDP) ligands were shown crystallographically to have an increased C−N−N−C torsion anglethis puckering resembles the structure of (R,R)-Ph-BPE and has a dramatic influence on regioselectivity in rhodium catalyzed hydroformylation. The red-BDPs demonstrated up to a 5-fold increase in selectivity for the branched aldehyde compared to the acylhydrazine parent ligands. This work demonstrates a facile procedure for increased branched selectivity from the highly active and accessible class of BDP ligands in hydroformylation.

p a1 t ung d e s tz-N a p h t o c h r om o n s d u r c h N a t r i u m a1 k o h o l it t.3 g des e-Naphtochromons wurden mit einer concentrirten, allioholischen Losung von 6 g metallischem Natrium einige Stunden :,uf dem Wasserbade am Rtckflnsskiihler gekocht. Alsdann wurde der Aikuhol durch Einleiten von Wasserdampf verjagt ond die Flussigkeit niit Schwefelsaure neutralisirt. Beim Einleiten von Kohlendioxyd svhied sich ein Korper Bus, der sich a19 2 -A c e t o -1 -n a p h t o l erwies Die vom 2-Aceto-1-Naphtol durch Ausathern hefreite Natriumbicarbonatlosung wurde mit Schwefelsiure angesauert und in die khre Lijsung Wasserdampf eingeleitet. Mit den Wasserdampfen destillirte eine Fettsaure, welche die Reactionen der A m e i s e n s a u r e gab und a1s Rleisalz isolirt wurde.Das a-Naphtochromon zerfiel beim Kochen mit Natriumalkoholat in ?-Aceto-1-naphtol und Ameisenssure nach folgender Gleichung:

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