939. Reduction reactions of organometallic compounds. Part I

Unusual orthometallation of a tetraphenylcyclopentadienone ligand

“…The carbonyl bond length of this tetracyclone is even longer than that of the other [C(35)-0(7) 1.378(9) A]. The oxygen of this carbonyl group, 0(7), forms a short intramolecular hydrogen bond with the other ketonic oxygen [0 (7) H -O(6) 2.590(7) A], thus explaining the 'H NMR signal at 6 11.0. Precedent for such an interaction is provided by complex 2; the 0 H 0 distance in the C4(C6H4Cl-p)4C0 analogue of 2, which was structurally characterised, was 2.54 A.'…”

“…The same phenyl group is bonded in an q6 manner to a third ruthenium atom, which in turn is ligated by the second tetracyclone (again bound a s a planar q5 ligand), forming a sandwich-type fragment. The hydrogen atom released by the metallation of C(30) is intramolecularly hydrogen bonded between the oxygen atoms of the two tetracyclone ligands [ 0 ( 6 ) H 9 O(7) 2.590 (7) A].…”

“…) 6359 (7) 7073 (6) 3 849( 7) 3800 (7) 3921( 4) 4697( 5) 5438 (7) 5870 (8) 6326 (7) 361 l(8) 3591( 8) 3034( 6) 2367( 6) 1496 (7) 1643 (7) 2627 (6) 2522 (6) 229 l (8) 2455 (8) 2858( 9) 3079( 8) 2900 (7) 475(7) -235 (8) -1208( 10) -1442 (9) -757 ( 11) 219 (10) 813(8) -156(9) -980(9) -871 (11) 53( 14) 4) 6336( 4) 3972( 2) 2944( 3) 5096( 4) 5543( 4) 4270( 4) 5977( 4) 5974 (5) 6 c w 3 ) 4261(4) 449 l(4) 4 78 6( 4) 4744( 4) 444 1( 4) 4418( 4) 4887( 5) 4802( 5) 4276( 5) 3807(5) 3 8 7 2( 4) 4976( 5) 45 3 2( 6) 4692( 9) 5321( 8) 5758( 8) 5605( 6) 4924( 5) 4619( 8) 5193( 7) 5625 (7) 4479 (7) X 918(…”

Organic Syntheses via Transition Metal Complexes. 86. Regioselective [C3 + C2] Cyclopentadiene Annulation to Enamines with Alkynylcarbene Complexes of Chromium and Tungsten as Novel C3 Building Blocks

“…In the past 10 years, α,β-unsaturated carbene complexes (= 1-metalla-1,3-butadienes) of chromium have gained critical acceptance as efficient tools for ring annulation reactions, which have greatly simplified the ability to assemble a variety of cyclic and polycyclic structures from acyclic precursors ,, Although this reaction is usually considered to yield six-membered 1,4-dioxyaryl compounds, a number of cases are reported where five-membered-ring carbocycles are produced by insertion of carbon monoxide (e.g., cyclopentenones, cyclopentadienones, and cyclopentendiones 13 ) or without insertion of carbon monoxide (e.g., indene derivatives, ,, cyclopentenes, cyclopentylidenes, cyclopenta[ b ]pyranes, and coordinated fulvenes ).…”

Nucleosides. XXVII. 3'-Amino-3'-deoxyhexopyranosyl Nucleosides. II. Synthesis of 1-(3'-Amino-3'-deoxy-β-D-glucopyranosyl) pyrimidines and Related Compounds1,2

“…This paper deals with a facile synthesis and a study of the chemical properties of 3'-amino-3'-deoxyhexosylpyrimidines which should have wide application in (9) Gougerotin, an antibiotic from Streptomycee gougerottii, was originally reported to have a 3-amino-3-deoxyallose structure in the molecule.10 This was corrected to the 4-amino-4-deoxygalactose structure.11 (10) H. Iwasaki, Yakugaku Zasehi, 82, 1387, 1393(1962. the nucleoside area.…”