Preparation, characterization, and reactions of 3-germabicyclo[3.2.1]octane and 2-germabicyclo[2.2.1]heptane derivatives

Structure of tetraspiro[1,3,5,7-tetraoxa-2,4,6,8-tetragermacyclooctane-2,1':4,1'':6,1''':8,1''''-tetrakisgerminane]

“…The C---Ge bond lengths [1.929 (5)-1.942 (7) A] are within the range of C(sp3)--Ge bond lengths [1.933 (6)-1.967 (3)A] previously reported for germacyclanes (Faucher, Mazerolles, Jaud & Galy, 1978;Preut, Krcher & Neumann, 1985;Sommese, Cremer, Campbell & Thompson, 1990). All the C---C--C angles (2) (Takeuchi, Shimoda, Tanaka, Tomoda, Ogawa & Suzuki, 1988), except for the bond angle Cring-----Gc ¢-~ for "~ring, which the calculation gave a significantly smaller value (101.9°).…”

The Role of Group 14 Element Hydrides in the Activation of C–H Bonds in Cyclic Olefins

“…This central core is a 3,9-digerma analogue of the hypothetical all-carbon molecule tricyclo[3.3.1.0 3,9 ]nonane. Germacyclohexane moieties are known and display similar geometry to that found in 10 . The Ge–Ge bond distance is normal for a single bond (c f., 2.44 Å in elemental germanium), indicating less strain than in the digermahypostrophene cage compound (ArGe) 2 (C 8 H 8 ) in which the Ge–Ge distance is found at 2.566(1) Å and is susceptible to thermolysis under mild heating .…”

Advances in Transition‐Metal‐Catalyzed Hydrogermylation of Alkenes and Alkynes†

“…Stone and co‐workers found that the Pt(0) complex [Pt(C 2 H 4 ) 2 (PCy 3 )] can react with HGeMe 3 to give a hydride‐bridged platinum germyl complex [Pt(GeMe 3 )( μ ‐H)(PCy 3 )] 2 , which can effectively catalyze the hydrogermylation of 1‐hexene with HGeMe 3 to afford n C 6 H 13 GeMe 3 in 80% yield (Scheme 2a). [ 55 ] Besides, H 2 PtCl 6 can catalyze the intramolecular hydrogermylation of bicyclo[2.2.1]heptane to form 2‐germabicyclo[2.2.1]heptane in 69% yield (Scheme 2b) [ 56 ] and the intramolecular hydrogermylation of 3‐hexenoxydipropylgermane to give 5‐propyl‐1‐germa‐2‐oxacyclopentane as the major product along with a six‐membered‐ring compound (6‐ethyl‐1‐germa‐2‐oxacyclohexane) (Scheme 2c). [ 57 ] Silyl‐substituted ethylenes can also react with HGeMe 3 under H 2 PtCl 6 to give alkylgermanes in 68%—78% yields with good to excellent regioselectivities (Scheme 2d).…”

“…The catalytic hydrogermylation reactions mainly include the following categories: free radical hydrogermylation initiated by photo‐ [ 32‐33 ] or thermal‐excitation, [ 34‐37 ] peroxides, [ 38‐40 ] organic boron reagents [ 41‐48 ] or others [ 49‐51 ] and transition‐metal‐catalyzed hydrogermylation. [ 9,52‐101 ] Transition‐metal‐catalyzed hydrogermylation has the potential advantages of selectivity control upon catalyst tuning.…”

“…The exploration on transition‐metal‐catalyzed hydrogermylation started quite early. Similar to the hydrosilylation reactions, the precious metals, such as Pt, [ 55‐59,82,84‐86,102‐103 ] Pd, [ 52‐54,74‐81 ] Rh, [ 61‐62,90‐94 ] Ru, [ 62,95‐98,104 ] have been found capacity of catalyzing the hydrogermylation of unsaturated carbon‐carbon bonds with good to high regio‐ and stereoselectivity. From an economic and green sustainable perspective, it is more desirable to develop new catalytic systems based on cheap and earth‐abundant metals to promote the hydrogermylation of unsaturated carbon‐carbon bonds.…”