Community-based forestry management is emerging as an important component of forest policies in the developing world. Using the Philippines as a case-study, this article critically examines the way in which communitybased forestry is constructed and understood among government policy makers. The author suggests that the new policy discourse of communitybased forestry policy in the Philippines is still shaped by efforts to maintain centralized control over forest management and a political economy orientated towards commercial timber production using the principles of`scientific management'. While timber production and the technical aspects of forest management are emphasized, social and environmental considerations remain neglected.
Recently, chalcogen bonding has been investigated in more detail in organocatalysis and the scope of activated functionalities continues to increase. Herein, the activation of imines in a Povarov [4+2] cycloaddition reaction with bidentate cationic chalcogen bond donors is presented. Tellurium‐based Lewis acids show superior properties compared to selenium‐based catalysts and inactive sulfur‐based analogues. The catalytic activity of the chalcogen bonding donors increases with weaker binding anions. Triflate, however, is not suitable due to its participation in the catalytic pathway. A solvent screening revealed a more efficient activation in less polar solvents and a pronounced effect of solvent (and catalyst) on endo : exo diastereomeric ratio. Finally, new chiral chalcogen bonding catalysts were applied but provided only racemic mixtures of the product.
Homoleptic LiNacNac forms simple
donor–acceptor complexes
with
N
,
N
′-dicyclohexylcarbodiimide
(CyN=C=NCy), triphenylphosphine oxide (Ph
3
P=O), and benzophenone (Ph
2
CO). These crystallographically
characterized compounds could be regarded as model intermediates en
route to reducing the N=C, P=O, and C=O bonds
of unsaturated substrates. Heteroleptic NacNacMg(TMP) intriguingly
functions as a TMP nucleophile both with
t
-BuNCO
and
t
-BuNCS, producing a urea or thiourea derivative
respectively attached to Mg, though the NacNac ligand in the former
reaction also engages noninnocently with a second
t
-BuNCO molecule via insertion at the reactive NacNac backbone γ-carbon
site.
Though alkali metal NacNac (β‐diketiminate) complexes have been utilised in synthesis as NacNac‐transfer agents, studies of them in their own right with small molecules are exceptionally rare. Here, the lithium compound of the common 2,6‐diisopropylphenyl‐β‐methyldiketiminate [NacNac(Dipp, Me)] ligand is investigated with carbon dioxide and isocyanates. In all four cases reaction occurs at the backbone γ‐C atom of the NacNac ligand, which redistributes electronically into a diimine. Insertion of CO2 gives an eight‐atom carboxylate (Li2O4C2) ring at the γ‐C site in a dimer. Insertion of tBuNCO gives a secondary amide at the γ‐C site in a monomer with TMEDA chelating lithium. Double insertion of tBuNCO and (adventitious) oxygen gives a dimer with a (LiO)2 central core involving the latter source. Insertion of less bulky (iPrNCO) gives a dimer with dimerisation through the C=O bonds of the emergent secondary amide function.
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