An endophytic fungus, Gliocladium roseum (NRRL 50072), produced a series of volatile hydrocarbons and hydrocarbon derivatives on an oatmeal-based agar under microaerophilic conditions as analysed by solid-phase micro-extraction (SPME)-GC/MS. As an example, this organism produced an extensive series of the acetic acid esters of straight-chained alkanes including those of pentyl, hexyl, heptyl, octyl, sec-octyl and decyl alcohols. Other hydrocarbons were also produced by this organism, including undecane, 2,6-dimethyl; decane, 3,3,5-trimethyl; cyclohexene, 4-methyl; decane, 3,3,6-trimethyl; and undecane, 4,4-dimethyl. Volatile hydrocarbons were also produced on a cellulose-based medium, including heptane, octane, benzene, and some branched hydrocarbons. An extract of the host plant, Eucryphia cordifolia (ulmo), supported the growth and hydrocarbon production of this fungus. Quantification of volatile organic compounds, as measured by proton transfer mass spectrometry (PTR-MS), indicated a level of organic substances in the order of 80 p.p.m.v. (parts per million by volume) in the air space above the oatmeal agar medium in an 18 day old culture. Scaling the PTR-MS profile the acetic acid heptyl ester was quantified (at 500 p.p.b.v.) and subsequently the amount of each compound in the GC/MS profile could be estimated; all yielded a total value of about 4.0 p.p.m.v. The hydrocarbon profile of G. roseum contains a number of compounds normally associated with diesel fuel and so the volatiles of this fungus have been dubbed 'myco-diesel'. Extraction of liquid cultures of the fungus revealed the presence of numerous fatty acids and other lipids. All of these findings have implications in energy production and utilization.

[structure: see text] A yttrium(III) complex derived from proligand 7c has been shown to be a superior catalyst for enantioselective intramolecular alkene hydroaminations that provide cyclic amines with ee's ranging from 69% to 89%.

The preeminence of chiral phosphines as controller ligands for a wide range of asymmetric processes has become firmly established. Although myriad examples of phosphines possessing carbon-centered chirality have been synthesized and subsequently evaluated in the above context, comparatively few P-chiral ligands have received scrutiny due to their relative inaccessibility. 2 In this paper, we show that a variety of P-chiral phosphine-boranes can be directly prepared from a racemic 2°-phosphine-borane precursor with excellent enantiocontrol via dynamic resolution/ alkylation of the corresponding lithium derivative in the presence of (-)-sparteine. [3][4][5] Studies on Dynamic Resolution. The racemic substrate selected for initial study, (()-tert-butyl phenylphosphine-borane (1), 6 was readily prepared in 52% overall yield by treatment of PhPCl 2 in Et 2 O with t-BuMgCl (1 equiv, -78 f 0°C) followed by direct reduction of the intermediate chlorophosphine (LiAlH 4 , Et 2 O) and complexation with BH 3 ‚SMe 2 (BMS) (Scheme 1). Lithiation of 1 with n-BuLi (1.0 equiv) in Et 2 O at -78°C in the presence of (-)-sparteine (1.3 equiv) furnished a nearly homogeneous solution which, upon warming to ca. 0°C, deposited a voluminous precipitate. Further warming of this suspension to ca. 25°C for 30 min followed by cooling to -78°C and alkylative trapping with 2-(chloromethyl)anisole 7 provided the corresponding scalemic phosphine-borane 2 in 74% yield. Analysis of 2 prepared in this manner by chiral HPLC using a CHIRALPAK AD column revealed its enantiomeric excess (ee) to be 88%. 8 Significantly, the extent of enantiomeric enrichment was found to be time and temperature dependent. Accordingly, reduction of the temperature in a typical dynamic resolution experiment to 30 min at 0°C resulted in a decrease in ee to 35%. By way of contrast, simple stirring of the suspended (-)-sparteine‚lithium complex of 1 for 1 h at 25°C prior to alkylation resulted in an increase in ee to 95%. 8 The absolute sense of optical induction was readily determined to be (R) by methylation (CH 3 I) of the (-)-sparteine‚lithium complex of 1 to secure tert-butylmeth-Having determined what appeared to be optimum conditions for the dynamic resolution of lithiated 1, a representative series of halides possessing a secondary ligating moiety were examined as alkylating agents. In all cases, scalemic phosphine-borane precursors to prospective bidentate ligands were produced with excellent enantiomeric differentiation and in good isolated yields (Table 1). 9 It is of interest in a preparative context that (1) Recipient of a Japan Society for the Promotion of Science Fellowship, 1997.(2) (a) For a recent review, see: Petrusiewicz, K. M.; Zablocka, M. Chem. ReV. 1994, 94, 1375-1411. (b) For the use of (-)-sparteine-mediated enantioselective deprotonation in the asymmetric synthesis of P-chiral diphosphines, see: Muci, A. R.; Campos, K. R.; Evans, D. A. J. Am. Chem. Soc. 1995, 117, 9075-9076. (c) For a route to stereogenic P-trisubstituted phosphorus by crystalliz...

No abstract

The catalyzed intramolecular hydroamination of carbon± carbon multiple bonds is one of the most important methods for the synthesis of nitrogen heterocycles. [1] Of the variety of metal-based catalysts for this transformation, complexes of the lanthanides appear uniquely well suited for effecting chemoselective alkene hydroaminations under mild reaction conditions. [2, 3] The vast majority of the complexes that have found utility for this purpose are comparatively air-and moisture-sensitive metallocene derivatives. We recently disclosed that simple amido derivatives of the Group 3 metals corresponding to the formula [Ln{N(TMS) 2 } 3 ] (1; Ln ¼ lanthanide, TMS ¼ trimethylsilyl) are competent catalysts for intramolecular alkene hydroamination. [4] Herein we show that catalytic activity can be dramatically increased and cyclization diastereoselectivity improved by coordination of the active metal center to simple chelating diamide ligands (Scheme 1).As part of our previous study, [4] we noted that the addition of representive amino alkenes to catalytic quantities COMMUNICATIONS